[单选题]
An object of mass m is hanging by a string from the ceiling vqkhq v:,7/k(oz) lnqof an eleva q2n o6ms 5bk0tb:y7fntor. The elevator is moving upw2y f76 on:0qb snb5mtkard, but slowing down. What is the tension in the string?
A. less than mg
B. exactly mg
C. greater than mg
D. zero
