The area of a circle is 16π. What is its circumference?

✓ Correct Answer: Option B

The area of a circle is A = πr^2. Given A = 16π, then πr^2 = 16π, so r^2 = 16, and r = 4. The circumference of a circle is C = 2πr. Substituting r = 4 gives C = 2π(4) = 8π.