Holly earns $30 for babysitting 5 hours. She earns $28 when she does chores for 4 hours. Which compares the unit rates?
A. The unit rate for babysitting is $2 per hour more than the unit rate for doing chores
B. The unit rate for babysitting is $1 per hour more than the unit rate for doing chores
C. The unit rate for doing chores is $1 per hour more than the unit rate for babysitting
D. The unit rate for doing chores is $2 per hour more than the unit rate for babysitting