The best inference you can make from the last four lines of the poem is:
D The speaker prefers to risk madness rather than endure the torture of a meaningless life.
This is supported by the lines indicating that while putting meaning in one's life may lead to madness, living without meaning results in restlessness and vague desires, which the speaker likens to a boat longing for the sea but being afraid. This suggests a preference for taking risks in pursuit of meaning rather than remaining stagnant and unfulfilled.