Which of the following statements about oceanic carbon chemistry is true?
a. air-sea equilibration is the only factor affecting the amount of carbon in the oceans
b. warm surface waters are enriched in dissolved carbon dioxide as compared to the cooler deep waters
c. the reaction between dissolved carbon dioxide and carbonate ions to form bicarbonate significantly enhances the ocean’s capacity to store carbon
d. as dissolved carbon dioxide concentrations in the oceans increase, we should expect bicarbonate concentrations to drop and carbonate ion concentrations to rise

(C) The reaction between dissolved carbon dioxide and carbonate ions to form bicarbonate significantly enhances the ocean’s capacity to store carbons.

Explanation:

ocean consumes mainly carbon dioxide from atmosphere. This is done by the process of photosynthesis performed by the plants like organisms in the sea known as phytoplankton. Through this process carbon dioxide dissolves in water further reacting with sea water creating carbonic acid. This carbonic acid leaves  hydrogen ions which later combines with carbonate to form bicarbonate. The result of formation of bicarbonate increases the capacity of sea to store the carbon which doesn’t escape the ocean easily.

So option (c) will be correct answer

a. european colonies