The highway transportation system has traffic deaths.
a)reduce
b)increase

This answer is reduce:

The Highway Transportation System has helped reduce traffic deaths.

If they increased it, that'd be terrible! 

Answer were lower;

Your answer is d. silli hope this ! : ) i left an explanation down below if you need it: a sill forms when hot magma squeezes between layers of rock to form a hardened sheet of rock. a sill is basically a tabular sheet intrusion between old layers of sedimentary rock, volcanic beds, or in the direction of foliation inherent in metamorphic rock. the word sill means a concordant intrusive sheet.