Which revision best combines these sentences to improve sentence variety and style?

Question

A. Made out of oak I built an extra bookcase because I had too many books; now it just needs to be varnished.
D. Because I had too many books, I built an extra bookcase made out of oak; now it just needs to be varnished."

Answer 1

D. Because I had too many books, I built an extra bookcase out of oak; now it just needs to be varnished.