Is the weather calm under the control of equatorial depression?

A, equatorial low pressure control area, prevailing updraft, more convective rain, so a is correct;

B, polar high pressure area control area, prevailing downdraft, sunny weather, so B is irrelevant;

C, polar easterly winds mostly come from the polar regions, which are cold and dry and have little precipitation, so C is irrelevant;

D, most of the trade winds are inland winds, and there is little precipitation, so D is irrelevant.

So choose: a.