Question

multiple-choice question coral bleaching is... coral polyps changing their pigment corals losing their symbiotic algae humans sanitizing coral reefs with bleach

Explanation:

Coral bleaching occurs when corals expel the symbiotic algae (zooxanthellae) living in their tissues, which provide them with color and nutrients. The first option is incorrect as it's not about pigment change by polyps. The third option is incorrect as humans don't sanitize reefs with bleach to cause bleaching.

Answer:

B. Corals losing their symbiotic algae