Approximately how much of the planet is covered in water?
a. one half
b. two-thirds
c. one-fourth
d. three-fourths

The oceans cover around 70 percent of the Earth's surface - so at least two-thirds (the other options one half and one-forth are out, since they're less than that)

The different sources mention 70, 71 and 72 percent - but they refer mostly to the oceans.

The exact answer is problematic, as it's only an estimation and it depends also on seasonal rivers which are not stable - but since even 72% of earth is covered by oceans, then i would say we can add the lakes and rivers and we will end up with 75% - answer d) (but i can imagine that some tests, depending on their sources want you to answer b)

The answer is c) people evacuated but almost all returned

Increasing the release of greenhouse gases and pollution