Cognitive development encompasses which of the following?

• A. Changes in memory and problem-solving
• B. Mental abilities, thinking, intelligence, and memory
• C. The growth of bones
• D. Social skills development

Answer: (B)

Cognitive development is about how thinking abilities grow and change over time, including how we remember, reason, solve problems, and use information to learn. The best choice captures this broad range by listing mental abilities, thinking, intelligence, and memory, which together represent the core processes people use to think and learn.

The other options point to parts of development outside cognition: growth of bones is physical development, and social skills development falls under social-emotional growth. A subset like changes in memory and problem-solving describes only a portion of cognition and misses other important aspects such as language, attention, and reasoning.