According to Gesell's theories, motor development can be sped up with exercise, but only to a limited extent.

• A. Motor development is entirely predetermined.
• B. Motor development depends solely on nutrition.
• C. Motor development can be sped up with exercise, but only to a limited extent.
• D. Motor development cannot be influenced by environment.

Answer: (C)

The main idea is that motor development proceeds largely according to a genetically guided timetable. Gesell emphasized maturation as the primary engine of development, with a fairly fixed sequence of motor milestones that tends to unfold in a similar order for most children.

Within that timetable, environmental factors like practice and physical activity can help a child refine movements and possibly achieve a skill a bit earlier or more smoothly, but they can only nudge development so far. They cannot overhaul the overall pace set by maturation, nor dramatically accelerate the entire sequence of motor growth.

That balance is why the statement is the best fit: it acknowledges that exercise and practice have a positive, though limited, influence on motor development without contradicting the idea that the timing and order of major milestones are largely predetermined. The other options overstate or misstate the role of maturation and environment, implying that development is either entirely fixed, driven only by nutrition, or entirely immune to environmental influence.