Given an ant crawling on the sphere x²+y²+z²−2x−2y−4z−3=0, how close and how far can the ant get from the origin?
a. The closest point is 3 units away; the farthest point is 7 units away.
b. The closest point is 2 units away; the farthest point is 5 units away.
c. The closest point is 1 unit away; the farthest point is 4 units away.
d. The closest point is 0 units away; the farthest point is 3 units away.