When does the car have the most kinetic energy 30 mph, 15 mph, or 0 mph

Kinetic energy is KE=0.5mv^2
Since the car is mass is the smallest efor the three situations
the Kinetic energy at 30 mph
KE1=0.5 m (30)^2
the Kinetic energy at 15 mph
KE2=0.5 m(15)^2
the Kinetic energy at 0 mph
KE3=0
KE1>KE2
The Kinetic energy at 30 mph is the highest

Alpha particles have positive charge, beta particles have negative charge, and answer 4 just doesn’t make sense. thus, you are left with only one possible answer.