The correct answer is The speaker loves the addressee as much as the speaker's soul allows (the first option).
This is evident from the opening line of the poem excerpt: "I love thee to the depth and breadth and height / My soul can reach...".
From these lines, the speaker makes it clear he/she is enamored with the addressee.
Option two is wrong because it states that the speaker loves the addressee despite the addressee not being graceful; the poem expresses that the addressee is graceful ("For the ends of being and ideal grace.").
Option three is wrong because the poem clearly expresses the opposite sentiment. ("I love thee to the depth and breadth and height".)