To save money for prom this weekend, Tom is going to walk his neighbor's dog for $6 per hour and wash cars for $7.50 per hour. His mother sid he can work no more than 15 hours to ensure he keeps up with his homework. Tom needs to make at least $75 to cover prom expenses. If d represents the number of hours walking his neighbor's dog and c represents the number of hours washing cars, which system of inequalities represents this situation? a
\large 6d+7.5c\le15

\large d+c\ge75

b
\large 6d+7.5c\le75

\large d+c\ge15

c
\large 6d+7.5c\ge75

\large d+c\le15

d
\large 6d+7.5c\ge15

\large d+c\le75