Step 1: Understanding hermatypic corals.
Hermatypic corals, also known as reef-building corals, thrive in warm, clear, and shallow waters. They require sunlight for photosynthesis, which makes the photic zone, or the shallow waters where sunlight penetrates, the ideal environment.
Step 2: Analyzing the options.
(A) the photic zone: This is a correct characteristic.
(B) warm and clear water: This is a correct answer because these corals thrive in tropical waters that are warm and clear.
(C) cool deep water: This is incorrect because hermatypic corals need warm, shallow waters.
(D) reefs: This is a correct answer because hermatypic corals are found in reefs.
Step 3: Conclusion.
The correct answer is (A), (B) and (D).