During the well-child assessment of an 18-month-old male toddler, the nurse determines the child does not walk while holding on to furniture but prefers to crawl, rarely speaks, has a flat affect, and is small for his age. Which nursing diagnosis should the nurse formulate?

a. Alteration in nutrition.
b. Alteration in parenting.
c. Delayed growth and development.
d. Alteration in health maintenance.