Final answer:
According to Piaget, when children encounter something familiar, they assimilate it; when they encounter something new, they accommodate it, corresponding with option (a). Assimilation integrates information into existing schemas while accommodation modifies schemas to incorporate new experiences.
Step-by-step explanation:
According to Piaget's theory of cognitive development, when children encounter something familiar, they assimilate it; when they encounter something new, they accommodate it. This means the correct answer to the question is (a) assimilate; accommodate. Assimilation occurs when new experiences are incorporated into pre-existing schemata, or frameworks, that are already understood by the child. For example, when 2-year-old Abdul sees various types of dogs and recognizes them all as dogs, he is assimilating the new instances into his existing schema for what a dog is.
On the other hand, accommodation happens when a child changes their schemata in response to new experiences that don't quite fit into any existing schema. This is a critical part of cognitive development, where the child learns to differentiate and integrate new information that doesn't match what they already know, thereby expanding their understanding of the world. If Abdul encounters an animal, such as a fox, he may initially call it a dog but then learn to adjust his schema of a dog to exclude foxes, which exemplifies accommodation.