The kinetic energies of a planet in an elliptical orbit about the Sun, at positions A, B and C are $K_A,K_B$ and $K_C$, respectively. AC is the major axis and SB is perpendicular to AC at the position of the Sun S. Position A is closest to the Sun (perihelion) and C is furthest (aphelion). Then:

According to Kepler's Second Law (Law of Conservation of Angular Momentum), the angular momentum $L=mvr$ is constant.At the perihelion (A), the distance $r$ is minimum, so the velocity $v$ is maximum. Thus, $K_A$ is maximum.At the aphelion (C), the distance $r$ is maximum, so the velocity $v$ is minimum. Thus, $K_C$ is minimum.At point B, the distance $r$ is intermediate.Order: $v_A>v_B>v_C⟹K_A>K_B>K_C$.