You are given a short paragraph, a question and two choices to answer from. Choose the correct answer based on the paragraph and write the answer(not the key).
Q: Paragraph: For a given medium such as air, sound has a slower speed at lower temperatures.
 Question: Ivan yells across a canyon in the morning when it is cold and again later in the afternoon when it is hot. During which time did his voice travel the slowest? 
 Choices: A)morning 
B)afternoon
A:
morning