Some areas of an ocean are known as dead zones. These zones form when excess organic material decomposes. This increased decomposition uses up the oxygen from the water. Which human activity is most affected by the increasing number of dead zones in the ocean?

A.
Offshore oil drilling, because water in dead zones is toxic
B.
Commercial fishing, because fish cannot survive without oxygen
C.
Commercial shipping, because dead zones change the course of ocean currents
D.
Sand mining, because oxygen is not available to form the sands on ocean beaches