Assertion (A): Four-year-old Riya cannot take into consideration the height and width of the two beakers at the same time while pouring the same amount of water into tall and wide beakers.
Reason (R): Riya is at Preoperational stage of cognitive development as per Jean Piaget.
Choose the correct option.

Correct option is A

Both (A) and (R) are true, and (R) is the correct explanation of (A).
Jean Piaget's theory of cognitive development suggests that children progress through distinct stages of cognitive development. One of these stages is the Preoperational stage, which typically occurs between the ages of two and seven. During this stage, children are still developing their cognitive abilities and have not yet fully acquired logical reasoning skills.
In this scenario, the assertion (A) states that four-year-old Riya cannot take into consideration the height and width of the two beakers at the same time while pouring the same amount of water into tall and wide beakers. This is consistent with the characteristics of the Preoperational stage, where children often struggle with simultaneous consideration of multiple variables.
The reason (R) provided states that Riya is at the Preoperational stage of cognitive development according to Jean Piaget. This aligns with Piaget's theory, which identifies the Preoperational stage as the developmental stage for children around four years old.
Therefore, both the assertion and the reason are true, and the reason correctly explains why Riya cannot consider the height and width of the beakers simultaneously. Hence, the correct option is A. Both (A) and (R) are true, and (R) is the correct explanation of (A).