Sentence Correction

Concerned at the increase in accident fatalities, Tennesse adopted a child-passenger protection law requiring the parents of children under four years of age to be restrained in a child safety seat.

A. parents of children under four years of age to be restrained in a child safety seat
B. the restraint of parents of children under four years of age in a child safety seat
C. that parents restrain children under four years of age in a child safety seat
D. that children be restrained under four years of age in a child safety seat by their parents.
E. children to be restrained under four years of age by their parents in a child safety seat

The correct answer is C but i think it's wrong as the option starts with 'that' after 'the' which sounds awkward. I didn't find any answer as correct answer.

Please share your views.

Thanks a ton!