What was the question for this implicit rationale, and corresponding answer?
Organisms cluster around hydrothermal vents in the ocean floor. Background Hot water vents form inside cracks in the ocean floor. Organisms cluster around cracks in the ocean floor.
 The answer: (A)
The question: What do organisms cluster around, in the ocean floor?
Options:
- (A) cracks
- (B) chemicals
- (C) limestone
- (D) crust
- (E) headaches
- (F) Nutrients
- (G) horses
- (H) dogs