Which of these is an opinion?

People have started cleaning Mount Everest.

A team collected more than 10,000 pounds of trash.

Mount Everest has many visitors each year.

D

Trash cans are needed to keep Mount Everest clean.

D. Trash cans are needed to keep Mount Everest clean.

Explanation:

Though one could argue that this is also a fact. (But, of the four options presented, this one is the correct response.)

Trash cans are needed to keep Mount Everest clean.

Explanation:

The first three are most likely facts, as they seem true and like they've happened. Letter D, seems a little biased, like some people might think that trash cans are needed, whilst other people might think not.