We are given that
y-scale is a distance in miles
x-scale is a time in hours
and we are given
The graph of the distance a car travels at a constant speed passes through the points (0,0) and (2,136)
so, points would be
(0,0)
x1=0 , y2=0
(2,136)
x2=2 , y2=136
so, slope would be speed
because speed = distance / time
we can use slope formula

now, we can plug values

miles per hour
so, option-B..........Answer