Ants are the most common life form on earth, ___________ tiny, their combined weight is greater than that of the combined weight of all humans

1. A.
   though
2. B.
   although
3. C.
   even though
4. D.
   as if

Ants are the most common life form on earth, ___________ tiny, their combined weight is greater than that of the combined weight of all humans.

   A. though         B. although       C. even though    D. as if

Ants are the most common life form on earth, _____ tiny, their combined weight is greater than that of the combined weight of all humans.

    A. though      B. although    C. even though    D. as if