Given the task definition and input, reply with output. 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).

Paragraph: The longer the exposure, the more light that the telescope can gather to make the image.
 Question: Mike needed to get a dark picture . In order to get the darkest photo, Mike made the exposure 
 Choices: A)longer 
B)shorter
shorter