Fill in the blank (_) in the following sentence from the following choices.
Sentence: His legs got stronger from pulling the sled instead of pushing the block, although _ was lighter in weight.

Choice 1: His legs got stronger from pulling the sled instead of pushing the block, although sled was lighter in weight.
Choice 2: His legs got stronger from pulling the sled instead of pushing the block, although block was lighter in weight.
Which of the choices is correct? Respond with only "1" or "2" and no additional text.
1
2. The sentence should read "His legs got stronger from pulling the sled instead of pushing the block, although the block was lighter in weight