If hot material rises and spreads in the mantle what tendency may develop at the surface?

Correct answer: Divergence or spreading

The key idea is that hot mantle material is less dense than the cooler material around it. Because of this difference, it can rise toward the surface. When the rising material reaches a higher level, it may move sideways and spread in different directions. This movement can pull or push the surface plates apart, producing divergence or spreading. Thus, option A describes the relevant surface tendency. The other choices do not represent the usual result of mantle upwelling: a river flood concerns flowing water, vegetation growth concerns biology, and complete contraction is opposite to spreading.

In simple terms, rising material creates an upward flow and spreading creates an outward flow. Together they are associated with divergent movement, especially at a divergent plate boundary or a spreading centre. The question asks what may develop at the surface, not for every detail of plate motion, so “divergence or spreading” is the most suitable answer. The supplied answer A is consistent with the basic convectional-current explanation. Confidence is high because the physical relationship between upwelling and surface spreading is a standard geography concept.