Which statement is TRUE according to the last paragraphs?l

A. After over 2 months investigated, reindeer populations were reported to decrease because of the increase of unwanted plant species.

B. Nearly a half of reindeer populations have reduced in the last two decades.

C. Beside the scarcity of food, diseases are also the cause of reindeer’s mortality.

D. The average temperature of the Earth has increased by 3.7C since 1990.