A Planet in Another Solar System Orbits a Star with a Mass

Multiple Choice

A planet in another solar system orbits a star with a mass of 4.0 x 10³⁰ kg.At one point in its orbit it is 250 x 10⁶ km from the star and is moving at 35 km/s.Take the universal gravitational constant to be 6.67 x 10^-11 m²/s² .kg and calculate the semimajor axis of the planet's orbit.The result is:

A) 79 x 10⁶ km
B) 140 x 10⁶ km
C) 290 x 10⁶ km
D) 320 x 10⁶ km
E) 590 x10⁶ km