A bunch of grapes is placed in a spring scale at a supermarket. The grapes oscillate up and down with a period of 0.70 s, and the spring in the scale has a force constant of 690 (N)/(m). What is the mass of the grapes?
a) 100 g
b) 200 g
c) 150 g
d) 250 g
e) 300 g