Answer:
The correct answer is "Though Ahab is physically weakened, his insanity has strengthened his will for revenge."
Step-by-step explanation:
In the above excerpt which is taken from chapter 41 of Moby-D*ck, the narrator tries to explain that even though Ahab is not physically strong enough, his insane side of the personality made him more capable than his sane side. He gained more strength from the insanity to take revenge.
Therefore, "Though Ahab is physically weakened, his insanity has strengthened his will for revenge", is the overall meaning of the excerpt.