Alizard lies on a rock to raise its body temperature this is a geothermy b ectothermy c hydrothermy d endothermy

The answer is ectothermy. Ectotherms are organisms with a body temperature thats largely determined by its external environment (Reptiles/ amphibians/ insects/plants). These organisms adjust their temperature behaviorally by things like basking and moving into the shade. They are animals whose regulation of body temperature depends on external sources, such as sunlight or a heated rock surface. 

They both determine the exact age of rocks.