Final answer:
Option B is the correct answer. The nurse should respond that fantasy and reality often blur for children at this age and it's a normal part of cognitive development.
Step-by-step explanation:
The nurse's best response to a mother concerned about her 4-year-old son's 'lying' would be B. Fantasy and reality often blur for children at this age and it's a normal part of a child's cognitive development.
At the age of 4, children are experiencing cognitive development where they begin to understand that people have thoughts, feelings, and beliefs that are different from their own. This development is known as theory-of-mind (TOM). Children at this age may engage in imaginative play and may have difficulty differentiating between truth and fantasy, which can lead to what may appear as lying.
It is important for the mother to understand that this behavior is normal and does not indicate intentional deception. By acknowledging the normal cognitive development of children at this age, the nurse can help alleviate the mother's concerns.