Answer:
Option A, The curiosity rover found sulfur compound in rocks
Explanation:
NASA had send Curiosity rover to Mars. After this accomplishment, lot of information about the rust colored planet has been obtained such as type of landscape, traces of water etc.
However detailed information about the planet has been obtained through Curiosity's Sample Analysis at Mars (SAM) which gave the information about the mineralogical and chemical composition of the planet. During this analysis, sulfur was found and hence option A is correct
