Why Must Lander Probes on Mars Be Sterilized Before Launch

Multiple Choice

Why must lander probes on Mars be sterilized before launch?

A) to prevent terrestrial microbes hitching a ride on the probe and contaminating the Martian surface
B) to prevent terrestrial microbes destroying the electronics in the probe during its passage to Mars
C) to prevent Martian dust from building up on the probe on the surface
D) to prevent Martian microbes from contaminating the lander probe