The ongoing process through which people grow in their ability to think, understand, solve problems, and make meaning.

• A. Chromosome 21
• B. Congenital Heart Conditions
• C. Cognitive Development
• D. Down Syndrome

Answer: (C)

Cognitive development is the ongoing process through which people grow in their ability to think, understand, solve problems, and make meaning. It covers how memory, reasoning, language, and problem‑solving skills become more sophisticated over time through maturation and experience, shaping how we interpret the world and tackle new challenges. This explains why thinking abilities unfold from simple ideas in early childhood to more complex strategies later on, and why we continue refining these skills across life. The other terms describe specific conditions or medical issues rather than a developmental process: one is a chromosomal condition, another a heart condition, and another is Down syndrome, a syndrome caused by a chromosomal change. They don’t capture the progressive growth of thinking and understanding, so they don’t fit the prompt as well.