A cart of mass 3.0 kg experiences four forces: 30 N upward, 30 N downward, 12.0 N to the left and 9.0 N to the right as the cart rolls across the table. What is the resulting acceleration of the cart? a
7.0 m/s2 to the left

b
4.0 m/s2 to the left

c
1.0 m/s2 to the left

d
27 m/s2 to the left

e
3.0 m/s2 to the right