Question

Which clause is subordinate?

A.
My uncle is a serious organic farmer.

B.
Who puts a lot of thought into his techniques.

C.
His squashes were the biggest in the county last year.

D.
For instance, he recycles garden waste in a compost pile.

Answer 1

D, because the subordinate clause "for instance" has the subordinate conjunction "for" so it is a subordinate clause. 
Hope this helps.