Question

Because pushing, pulling, and controlled sagging are used in shaping glass, glassblowers are surely very skilled.

How can this sentence be made more clear and concise? If the sentence above is the BEST choice, choose "correct as is."
A.
Glassblowers are surely very skilled because pushing, pulling, and controlled sagging are used in shaping glass.
B.
Although pushing, pulling, and controlled sagging are used in shaping glass, glassblowers are surely very skilled.
C.
Glassblowers, who use pushing, pulling, and controlled sagging while shaping glass, are surely