Astronomical unit is roughly the distance from Earth to the Sun ( or 149,597,870,700 m ).
Mars can be between 0.53 au and 2.52 au from Earth, depending on their relative positions. In both cases we will not accept answers B), C) and D).
If we use the closest range:
0.53 au : 3.6 au/year = 0.1472 ≈ 0.15 years
Answer: A)
