Answer:
A certain cool headed ness had come to him
Doggedly he swam in that direction, swimming with slow deliberate strokes conserving his strength
Explanation:
These show that he can stay calm and logical even when forced into stressful situations.
When he says "My will to her consent is but a part; An she agree, within her scope of choice Lies my consent and fair according voice." He is saying here that his consent to Juliet and Paris' marriage is "but a part" of the decision, so he believes that her choice is also needed. He says that, while his "consent and fair according voice" may play a part in her choice, she still has a choice, free will.
Answer:
I think C would be the best choice.