Answer:
B and C
Step-by-step explanation:
The analogy bacon:pigs shows a comparison between pigs, a source, and bacon, a product derived from pigs.
A) The analogy metal:clouds doesn't show this comparison. Neither is a product of the other.
B) The analogy paper:trees shows this comparison because paper is a product derived from trees, a source.
C) The analogy cows:butter, shows a comparison of cows, a source and butter, a product derived from cows.
D) The analogy wood:leaves doesn't show this relationship. Neither is a product of the other.
Therefore, the matching analogies are B and C.
I hope this helps!