The answer is:
d. thy firmness makes my circle just/and makes me end
In John Donne's poem "A Valediction Forbidding Mourning," the author intends to express his desire to have a peaceful death in which his wife does not mourn him. He suggests their love is so strong that it goes beyond the physical state and will continue after death. Morever, he compares their love to a compass - his wife is the foot of the compass, which helps him create a perfect circle. As a result, he implies his wife's strength makes him complete and have a dignified and respectable death.
