Answer:
I believe the answer is C
Explanation:
Hope this helps!
The correct answer is B. Mysterious
Unfathomable means not being able to be understood or explained, which is, mysterious.
This is a sonnet by Elizabeth Barrett Browning which means that it is written in a Iambic Pentameter.
Words like : angry, my foe, my wrath, fears, deceitful, and glad
The last one is it(:
hope this helps you
-denis