Studies indicate that acidification of the ocean by the absorption of carbon dioxide is harmful to virtually all marine life and ecosystems. the group most vulnerable to both warming and acidification would be the

the Calcifying species

Explanation: These species of organisms, like the phytoplanktons depends on calcium carbonate minerals to form hard shells. However, due to the acidification of the ocean by the addition of carbon dioxide which react with water to form carbonic acids, the carbonate minerals become inhibited thereby causing harm and slow growth rate to those species of organisms.

l dont know l am s sorry

the answer is option a.