Sentence Correction (SC) | Re: Between 14,000 and 8,000 b.c. the ice cap that covered northern Asia,

Hiegmat GMATNinja I have a query in option A

A) Began to melt, uncovering

, verb + ing form shows cause and effect which is perfect in this case.

However, I eliminated this option based on the "to" after began. Does the "to" not indicate the purpose of began. I.E. the ice caps began in order to melt. This got me confused and I eliminated option A. Can you please explain when we use "to" for purpose and when we use itotherwise.