Oceans have absorbed approximately one-third of the excess carbon dioxide that humans have added to the Earth's atmosphere so far. This has slowed the progression of global climate change, but it has led to .

A) growth of oyster populations worldwide
B) loss of oxygen from the oceans
C) a decrease in the pH (ocean acidification)
D) an increase in the pH of the world's oceans
E) increases in growth of coral reefs