Teacher: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).
Teacher: Now, understand the problem? Solve this instance: Paragraph: By using multiple stages, empty fuel containers could drop away. This reduced the mass of the rocket so that it could fly higher.
 Question: If Mary is building a rocket and she wants it to fly as high as possible, what should she do to the mass of the rocket? 
 Choices: A)increase it 
B)decrease it
Student:
decrease it