Question

Which words in the sentence make up the adjective phrase?
Which word does the adjective phrase modify?

The horn-like tip of a strong feather makes a quill pen when it is sharpened.

A.
it is sharpened; modifies when

B.
a quill pen; modifies feather

C.
horn-like tip; modifies sharpened

D.
of a strong feather; modifies tip