Which one of the following pieces of evidence SUPPORTS the existence of tectonic activity in the Martian past?
A) The crust is everywhere thicker than Earth's crust.
B) There are large,isolated hot-spot volcanoes.
C) Valles Marineris,a long valley system,has been observed.
D) There is no planet-wide magnetic field.

Question

Quizplus · Accepted Answer

Valles Marineris is a long valley system on Mars that scientists believe was formed as a result of tectonic activity. This supports the existence of past tectonic activity on Mars. The other choices do not necessarily indicate past tectonic activity, as thick crust and isolated hot-spot volcanoes can also have other causes, and the absence of a planet-wide magnetic field does not necessarily indicate tectonic activity.

Which One of the Following Pieces of Evidence SUPPORTS the Existence