Which is the best way to write the two clauses as a complete sentence?

Pamela played so hard. She was very tired.
Though Pamela played so hard, she was very tired.
Because Pamela played so hard, she was very tired.
Pamela played so hard whenever she was very tired.
Pamela played so hard as she was very tired.

Question

Which is the best way to write the two clauses as a complete sentence? 

Pamela played so hard. She was very tired.
Though Pamela played so hard, she was very tired.
Because Pamela played so hard, she was very tired.
Pamela played so hard whenever she was very tired.
Pamela played so hard as she was very tired.

anonymous · Answer

what do you think @studystagram

anonymous · Answer

im thinking C.

studystagram · Answer

Because Pamela played so hard, she was very tired.

anonymous · Answer

nailed it :) lol

anonymous · Answer

I would say B

anonymous · Answer

"Because Pamela played so hard...etc"