Achild who is capable of reversibility can a. center on just one aspect of a problem, rather than focus on several aspects at once. b. focus on relations between a general category and two specific categories at the same time. c. order items along a quantitative dimension. d. think through a series of steps and then mentally reverse direction.

The correct answer is d.think through a series of steps and then mentally reverse direction.

Reversibility is the understanding and awareness that mental or physical operations can be reversed. For instance if a task requires eight sequential steps to be completed, a child who is capable of reversibility will  be aware that the eight steps can be reorganized or reversed and/or replaced by a different set of steps.