This could be false. We don’t know which planet is subject to less erosion than the other, and we have no information to suggest whether this is true or false.

This could be false. It could be that Mars’s thick crust is necessary for large volcanoes to form, but other factors determine how large they can get. In other words, a thick crust could be necessary, but not sufficient, for large volcanoes.

This could be false. We only know about one very large volcano on Mars. For all we know, all the other volcanoes could be very small and Earth’s are, on average, higher.

This must be true. The stimulus tells us that Earth cannot support such large volcanoes because its crust is too thin. This implies that Mars’s crust is not too thin (i.e., it is thicker), which enables it to support such a large volcano.

This could be false. It could be that crust thickness determines whether large mountains can form, but other factors determine whether they end up forming and how big they get. It could be that a thick crust is necessary, but not sufficient, for large volcanoes.