In this task, you're given a question, along with three passages, 1, 2, and 3. Your job is to determine which passage can be used to answer the question by searching for further information using terms from the passage. Indicate your choice as 1, 2, or 3.
Q: Question: Is the University of Mumbai larger than the first school Easwaran did his post-doctoral research at? Passage 1:NSB Class 73 () is a class of 22 electric multiple units built by Adtranz for the Norwegian State Railways. The four-car trains were modifications of Class 71, which was again based on the Swedish X2. The A-series consists of 16 intercity trains; they were delivered in 1999 and 2000 and are used on the Bergen, Dovre and Sørland Lines. The intercity service was branded as Signatur until 2003. The B-series consists of six regional trains delivered in 2002 and used on the Østfold Line. The regional trains were originally part of the Agenda concept. The trains have a power output of and a maximum speed of . They have an overall length of and have a capacity for 208 seated passengers in the A-series and 250 in the B-series. The trains have a tilting mechanism allowing for faster travel through curves.
 Passage 2:Sculptures of Tubman have been placed in several American cities. A 1993 Underground Railroad memorial fashioned by Ed Dwight in Battle Creek, Michigan features Tubman leading a group of slaves to freedom. In 1995, sculptor Jane DeDecker created a statue of Tubman leading a child, which was placed in Mesa, Arizona. Copies of DeDecker's statue were subsequently installed in several other cities, including one at Brenau University in Gainesville, Georgia. It was the first statue honoring Tubman at an institution in the Old South. The city of Boston commissioned Step on Board, a 10-foot-tall bronze sculpture by artist Fern Cunningham placed at the entrance to Harriet Tubman Park in 1999. It was the first memorial to a woman on city-owned land. Swing Low, a 13-foot statue of Tubman by Alison Saar, was erected in Manhattan in 2008. In 2009, Salisbury University in Salisbury, Maryland unveiled a statue created by James Hill, an arts professor at the university. It was the first sculpture of Tubman placed in the region where she was born.
 Passage 3:Kalpathy Easwaran, born on 7 July 1939 in the South Indian state of Kerala in a brahmin family, graduated in science from Government Victoria College, Palakkad and secured his master's degree (MSc) from the University of Mumbai in 1962 to pursue his doctoral studies at the department of physics of the Indian Institute of Science, which he obtained in 1967. His post-doctoral research was at Tata Institute of Fundamental Research during 1966–67 and later at the University of Washington after which he spent a year at Jožef Stefan Institute as a visiting scientist. Returning to India in 1970, he resumed his career at the Indian Institute of Science, holding such positions as Astra Chair professorship (1994–97), Chair of the department of molecular biophysics (until 2006) and as Indian National Science Academy Senior Scientist (2006–07) until his superannuation in 2007. In between, he served as a visiting faculty at institutions such as Harvard Medical School, University of Connecticut, Georgetown University, United States Naval Research Laboratory and National University of Singapore. Post retirement, he is involved with ABL Biotechnologies, a Chennai-based biotechnology institution.

A:
3