Which of these fits gap 17?

Directions: Complete this passage by selecting the most suitable option for the corresponding gap.
One _____ (17) _____ wear a helmet while riding a bicycle.
The risk of serious head injury is ______ (18) _____ as much as 85% and the risk of brain injury by as much as 88% if a bicycle rider wears a helmet.
If all the bicycle riders between the ages of 5-14 wore helmets while riding, at least 150 deaths and a hundred thousand nonfatal head injuries ______ (19) _____ prevented each year.

It is sorrowful that less than one in four children between the ages of 5-14 wear bicycle helmets while riding, and most teens _____ (20) _______ it.