Tom is riding a hot air balloon by himself. There is a rope ladder hanging from the top of the balloon and reaching into the basket. At a moment when the balloon is stationary in the air, Tom begins climbing the ladder with speed s relative to the ladder. Suppose Tom has mass m, the balloon has mass M. What is the speed of the balloon relative to the ground if air resistance can be neglected?
a) s
b) Mms
c) M+mms
d) M+mms
e) 0