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​