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