Suppose an Asteroid Is Discovered with an Elliptical Orbit, a Period

Multiple Choice

Suppose an asteroid is discovered with an elliptical orbit, a period of exactly 1 year, and perihelion 0.5 au from the Sun. Using Kepler's third law, how far from the Sun is this asteroid at aphelion? (Drawing a diagram of the orbit, including the Sun, will help.)

A) 2.5 au
B) 2.0 au
C) 1.0 au
D) 1.5 au