Task: Question Answering
Input (English): Why is Mars red?
(A)Because the surface is covered with heavily oxidized ("rusted") minerals. (B)Because the atmosphere scatters more light at bluer wavelengths transmitting mostly red light. (C)Because Mars is covered with ancient lava flows which are red in color. (D)Because flowing water on Mars's surface altered the surface minerals several billion years ago.
Output (English): A