Which statement about motor development is true?
a. motor skills are interrelated. "
b. motor skills are separate, innate abilities. "
c. children acquire motor skills on a fixed maturational timetable.
d. children acquire motor skills in the sequence implied by motor norms.

(a) Motor skills are interrelated.

Explanation:

As per the question,

Motor development:

It is defined as the development of movement abilities such as the development of a child's bones, muscles and ability to move around and manipulate his or her environment.

Importance of a Motor Development Model  are:

(1) Helps us make sense of developmental changes

(2) Provides a framework for observing the change

(3) Helps us include important factors of motor behavior in our observations.

Hence, Only option (a) is correct.

there are no correct statementd on the list of choices you provided.