Depending by how answer choices you can pick I'd say three. So, the correct answers would be D, A, and E.
The research demonstrated that <span>individuals improve most mental abilities during adulthood and then experience a gradual decline.
After people surpassing the mid-age, regeneration of the brain cells will also start to decline, which resulted in the impairment of cognitive ability that played a crucial role in our analytic ability.</span>
Answer: According to Piaget, May Lin's ability to use a doll as a representation of a real baby illustrates that she is capable of: SYMBOLIC FUNCTION.
Explanation: Symbolic function in Piagetian theory illustrates the ability of an individual to mentally use an object (the doll) to represent something that is not physically present (her baby brother).