Algae living within the tissues of corals play a critical role in keeping corals, and the marine ecosystems they are part of, thriving. Some coral species appear brown in color when healthy due to the algae colonies living in their tissues. In the event of an environmental stressor, the algae can die or be expelled, causing the corals to appear white. To recover the algae, the bleached corals then begin to produce bright colors, which block intense sunlight, encouraging the light-sensitive algae to recolonize the corals.

Question

What does the text most strongly suggest about corals that produce bright colors?
Choose 1 answer:
Choose 1 answer:
(Choice A) These corals are likely more vulnerable to exposure from intense sunlight than white corals are.
A
These corals are likely more vulnerable to exposure from intense sunlight than white corals are.
(Choice B) These corals have likely been subjected to stressful environmental conditions.
B
These corals have likely been subjected to stressful environmental conditions.
(Choice C) These corals have likely recovered from an environmental event without the assistance of algae colonies.
C
These corals have likely recovered from an environmental event without the assistance of algae colonies.
(Choice D) These corals are more likely to survive without algae colonies than brown corals are.
D
These corals are more likely to survive without algae colonies than brown corals are.

Answer 1

(Choice B) These corals have likely been subjected to stressful environmental conditions.

This is suggested by the fact that the corals have bleached and then produced bright colors in an effort to recover from the environmental stressor that caused the algae to die or be expelled. Bright colors are a response to stress in corals.