Consider a melt that has cooled to a temperature such that olivine, pyroxene, amphibole, and calcium-rich plagioclase feldspar have crystallized. which elements will be enriched in the melt, and which will be depleted in the melt?

Calcium is enriched, while they are depleted of carbon.

Explanation:

It should be understood that during the process of volcano eruption, carbon is liberated as the molten magma is coming out , this is due to the heat that is being evolved. And calcium will be the molecules that will make the molten solidified after wind has cooled it down.

That is why they are depleted of carbon, and enriched with calcium.

if the hares very faster than they are now, and thus the lynx's hunting success rate drops because it will be harder to catch them, the rate that will change will be the pray-rate. the pray-rate will change because more hares will be able to survive, thus more individuals for reproduction, so the end result will be increasing population of hares.

the predator-rate will remain pretty much the same because there will be more than enough pray, but the hunting success rate is stagnant.

b is the answer and if you need further with anything message me