Final answer:
Alyssa's understanding of conservation indicates that she is in Piaget's concrete operational stage of cognitive development.
Step-by-step explanation:
Alyssa's ability to grasp that the number of items (pennies) remains the same regardless of the arrangement or spacing represents a cognitive skill known as conservation. According to Jean Piaget's stages of cognitive development, Alyssa appears to be in the concrete operational stage, which typically encompasses ages 7 to 11. In this stage, children can think logically about concrete events, meaning they can understand that altering the appearance of an object does not change its quantity, mass, or volume.