(1) around 5000 B.C.E., the first animals were domesticated and tamed. (2) donkeys and oxen were used to carry heavy loads and pull sledges. what is the best way to combine sentences 1 and 2?

Question

a. around 5000 B.C.E., the first animals were domesticated and tamed, especially donkeys and oxen, used to carry heavy loads and pull sledges.
b. around 5000 B.C.E., the first animals were domesticated and tamed; especially donkeys and oxen, which were used to carry heavy loads and pull sledges.
c. around 5000 B.C.E., the first animals were domesticated and tamed, especially, donkeys and oxen which were used to carry heavy loads and pull sledges.
d. around 5000 B.C.E., the first animals were domesticated and tamed, especially donkeys and oxen, which were used to carry heavy loads and pull sledges.

Answer 1

i got d as the answer, is it right?

Answer 2

Either D or A -- but I think D is better.

Be sure you write with capital letters in the right places. If you wrote any of these sentences in my classes, they'd all be marked incorrect!