Answer: Option (a) is the correct answer.
Explanation:
When [tex]CO_{2}[/tex] is released from driving cars, some of which is absorbed by the plants but the rest of [tex]CO_{2}[/tex] reacts with the sea or ocean water.
It reacts with water molecules and changes the chemistry of ocean water by lowering its pH. As it is known that when pH becomes lower then the substance becomes acidic in nature.
Thus, we can conclude that driving cars lowers the pH of the oceans by releasing [tex]CO_{2}[/tex] that dissolves and forms acid in the oceans.