I think the answer to this is structure C
Meteorites remains are most commonly found in Antarctica. The reason for this is because of the fact that Antarctica is covered in snow and ice. In such conditions black meteorites are easier to spot and retrieve than <span>finding them in a camouflage environment or urban area. </span>
Answer is b. Burning fossil fuels causes a decrease in the pH of ocean water making it more acidic.
Burning of fossil fuels release carbon dioxide and other harmful gases in the atmosphere. Carbon dioxide gets dissolves in the ocean to form carbonic acid. Due to formation carbonic acid, the pH of ocean water changes slightly. The average pH of ocean water was 8.2 slightly basic. Now it 8.1, it means there is 25 % increase in acidity of ocean water.