Sentence Correction

Until recently, the Inuit people led a nomadic existence, sheltering in igloos, the ice-block domes that are peculiar to north-central Canada, and in structures made of stones, bones, driftwood, and skins.

A. Until recently, the Inuit people led a nomadic existence, sheltering
B. During recent times, the Inuit people lead a nomadic existence,
sheltering.
C. In the times that are recent, the Inuit people led a nomadic existence,
sheltered.
D. Up until recently, the Inuit people, leading a nomadic existence,
have sheltered.
E. Until recent times, leading a nomadic existence, the Inuit people
were sheltered.

This problem is from verbal Set 24. The OA given is D. I went for A during the test, though was little tentative on it.

Could any experts please explain the transition of this sentence and why other options are Incorrect, speciallyA ?

Thanks in Advance!!