As a result of additional carbon dioxide in the atmosphere diffusing into the oceans, the water has become acidified. This is an example of:

Ocean acidification

Explanation:

Ocean acidification is the progressive decrease in the pH of the oceans on Earth as the increasing amount of carbon dioxide CO₂ in the atmosphere which is due mainly to fossil fuel combustion, is dissolved into the oceans

Carbonic acid is formed when carbon dioxide, CO₂, in the atmosphere is dissolved in the ocean water to form carbonic acid as follows;

CO₂ + H₂O → H₂CO₃

H⁺(aq) ⇄ HCO₃⁻ (aq)

According to L e C h a t e l i e r ' s an increase in the amount of carbon dioxide in the atmosphere will result in more CO₂ dissolving into the oceans and forming more carbonic acid, HCO₃⁻ (aq), thereby increasing the acidity of the oceans which is equivalent to a reduction in the pH of the ocean waters.

the answer is c

tell me if wrong