According to What We Now Know from Newton's Laws, Which

Multiple Choice

According to what we now know from Newton's laws, which of the following best explains why Kepler's second law is true?

A) A planet's total orbital energy must be conserved as it moves around its orbit.
B) Gravity is an inverse cube law.
C) This effect happens because of the influence of other planets on a particular planet's orbit.
D) Orbits must be elliptical in shape.