Microscopic plants called algae

[poonamchiK]

Microscopic plants called algae grow inside the top layer of sea ice in the Antarctic if enough sunlight reaches that layer of ice and enough seawater, which contains nutrients, reaches that layer after splashing onto the surface. Even though moderate snow cover reduces the sunlight that filters into the top layer, sea ice with moderate snow cover typically contains even more algae in the top layer than does sea ice with less snow cover.

Which of the following, if true, most helps to explain the apparent discrepancy?

(A) As the weight of accumulated snow forces ice lower in the water, more seawater splashes onto the surface and seeps through the snow.

(B) Seawater in the Antarctic often contains higher concentrations of nutrients than does seawater in more temperate regions.

(C) As the air temperature around sea ice decreases during the winter, the likelihood decreases that snow will fall and thus add to any existing snow cover.

(D) The nutrients on which algae rely are common in seawater throughout the Antarctic.

(E) More sunlight filters through a layer of ice than through an equally thick layer of snow.

Highlight this to A see the answer.

I thought this is a good question and I havent seen this posted onto the forum.
P

[RonPurewal]

according to the problem, there are two requirements to grow algae:
(1) enough sunlight
(2) enough seawater

in the situation described in the passage, the total amount of sunlight is lower, but more algae actually grow. according to the conditions given above, the only way this could happen is if more seawater somehow gets in (since there is less sunlight, and that's the only other factor that's mentioned).
therefore, you are looking for a way in which more seawater will be admitted in the situation described.

this requirement is satisfied only by choice (a).