Answer:
c: -7.25
Step-by-step explanation:
Here we can use the equation v=u+at
Where v is the final velocity
u is the initial velocity
a is acceleration
and t is time
41.55=79.33+a(5.21)
41.55-79.33=5.21a
-37.78=5.21a
a=-7.25 m/

The negative sign is due to the fact that they are slowing down