According to contemporary theorists,an understanding of the effects of one's behaviors on others develops as a childs A.object performance B.theory of mind.C.sensorimotor operrations.D.theory of operations.

To determine the correct answer to this question, we need to understand what each option means and then match it with the one that best fits the description given. Let's go through each option:

A. Object performance: Object performance refers to a child's ability to understand that an object exists even when it is not visible. This does not directly relate to understanding the effects of one's behaviors on others.

B. Theory of mind: Theory of mind is the understanding that others have thoughts, beliefs, and intentions that may differ from one's own. This is closely related to understanding the effects of one's behaviors on others, as it involves recognizing that one's actions can have an impact on how others think or feel.

C. Sensorimotor operations: Sensorimotor operations are the mental processes through which a child learns to coordinate sensory input with motor actions. This does not directly relate to understanding the effects of one's behaviors on others either.

D. Theory of operations: "Theory of operations" is not a commonly known term in psychology or child development. It is not relevant to the question.

Given the descriptions above, the option that best matches the understanding of the effects of one's behaviors on others is B. Theory of mind.