Question

what is the name of the island that has some of the warmest temperatures shown on the map? hainan island hong kong haikou harbin

Explanation:

Hainan Island is a large island in southern China known for having some of the warmest temperatures in the country. Haikou is the capital city on Hainan Island, Hong Kong is a special administrative region (not primarily an island defined by this warm climate context here), and Harbin is a northern mainland city with cold temperatures.

Answer:

A. Hainan Island