Coral bleaching most often takes place in the shallowest parts of a reef. this would indicate which of the following? the shallow parts have more polyps. the shallow parts are more susceptible to temperature. the shallow parts have more starfish. the shallow parts have more invasive species.

Coral bleaching can be defined as a condition in which occurs in the corals during the stress conditions.

Due to increase in the temperature of the surrounding water corals generally expel the algae that was living in the coral and due to this the corals appear white.  

This is caused in the shallow parts because they are more susceptible to temperature change.

Hence, the correct answer is option B