The minimum and maximum distances of a planet revolving around the sun are x1 and x2. If the minimum speed of the planet on its trajectory is v0, then its maximum speed will be:

a. v₀ √x₂/x₁
b. v₀ √x₁/x₂
c. v₀ (x₂/x₁)²
d. v₀ (x₁/x₂)²