Rita drove a total of 120 miles at 40 miles per hour. tom drove a total of 100 miles at 50 miles per hour.

which explanation correctly describes a way to calculate the total number of hours rita and tom drove?

a.
step 1 divide: 120 ÷ 40
step 2 divide: 100 ÷ 50
step 3 add the two quotients.

b.
step 1 divide: 120 ÷ 40
step 2 divide: 100 ÷ 50
step 3 subtract the two quotients.

c.
step 1 add 120 + 40.
step 2 add 100 + 50
step 3 divide the two sums by 2.

d.
step 1 subtract 120 – 40.
step 2 subtract: 100 – 50.
step 3 divide the two differences by 2.

plz i need