Given the stream of consciousness rationale, provide a reasonable question and answer. Rationale: At 17 hours the one plant will take up 1/4 of the lake (1/2 of 1/2). At 17 hours the two plants would be double the size of the one plant and double 1/4 is one half.
 The question and answer:
user
You have found a mutant algae that doubles in size every hour. It takes 18 hours for one algae plant to take up half of a certain lake.
How long would it take for two of these plants to take up half of the same lake?
Options:
(A) 7
(B) 17
(C) 27
(D) 37
(E) 47
The answer is (B)
assistant