Need to identify the faulty strip by asking questions on the phone [on hold]

A set of vertical window blinds has 32 horizontal strips and one of the strips is faulty (does not move with the rest). You need to identify the faulty strip by asking questions on the phone. You can only ask questions about whether a strip at a certain number is faulty or not and the owner can only reply in ‘Yes’ or ‘No’. What is the least number of questions you must ask in order to identify the faulty strip?

A. 7

B. 8

C. 4

D. 5

E. 32

F. 16

Answer: ?