I am not sure about this one but I feel its a cause and effect scenario. Something happens which spees up the rotation ( Passive) One more thing to consider here is the possesive use of Earth. Earth does not increase roatation here. Earths rotation is increased.
Also use of like vs just as .
I think like should be used here.
( Aplogies if my explanation is completely off the track because I am not sure)
So yeah I'll go for B here
(sorry for the repost)
During an ice age, the buildup of ice at the poles and the drop in water levels near the equator speed up the Earths rotation, like a spinning figure skater whose speed increases when her arms are drawn in.
A. like a spinning figure skater whose speed increases when her arms are drawn in
B. like the increased speed of a figure skater when her arms are drawn in can be written as like figure skater's increased speed when her arms are drawn in
C. like a figure skater who increases speed while spinning with her arms drawn in
D. just as a spinning figure skater who increases speed by drawing in her arms
E. just as a spinning figure skater increases speed by drawing in her arms