Thinking is an inner activity in which the mind works upon materials that stand for things instead of upon the things themselves. Psychology lists these materials as images, signs, language and the generalised ideas formed from properties shared by many objects.

A generalised idea of that kind lets the mind hold a whole class of objects as a single unit, so that reasoning can move quickly from one class to another instead of dealing with every object separately. Without such units thought could never go beyond what is present to the senses at the moment, and no classification, judgement or inference would be possible.

A liking for an activity and the inner push towards a goal decide whether a person will think about a matter at all and for how long, but they are not the material with which thinking is actually carried on. Since a genuine instrument of thought is present among the alternatives, the denial choice is ruled out.

Concept option is correct.