Two carts, A and B, are pushed separately along a frictionless horizontal track by identical constant horizontal forces of magnitude 10N. Cart A has mass 2kg, and cart B has mass 4kg. Which of the following correctly compares the magnitudes of their accelerations aA and aB?
a) aA=aB
b) aA=2aB
c) aA=21aB
d) aA=4aB