Order of sentence

Could you tell me which sentence has most natural order among the following sentences?
If any of them just sound awkward or wrong, please tell me about them.
Thank you.

A. At the opening of this century, we should implement new policies that reflect the rapid depletion of the world's energy resources.

B-1. We should implement at the opening of this century new policies that reflect the rapid depletion of the world's energy resources.

B-2. We should implement, at the opening of this century, new policies that reflect the rapid depletion of the world's energy resources.

C. We should implement new policies at the opening of this century that reflect the rapid depletion of the world's energy resources.