Which of these describe a divergent plate boundary?
A. Two continental plates moving away from each other, forming a rift valley
B. Two oceanic plates rubbing against each other, forming a mid-ocean ridge
C. Two oceanic plates colliding, forming a volcano
D. Two continental plates colliding, forming a mountain range

A. Two continental plates moving away from each other, forming a rift valley

Explanation:

The google description is:

A tectonic boundary where two plates are moving away from each other and new crust is forming from magma that rises to the Earth's surface between the two plates.

Based on that you can infer that A. Two continental plates moving away from each other, forming a rift valley

is the best answer.

though getting a second opinion might be best cause I am no expert in this subject.

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.