A 4.0-m-diameter playground merry-go-round, with a moment of inertia of 300 kg⋅m2 is freely rotating with an angular velocity of 2.5 rad/s .Ryan, whose mass is 60 kg , runs on the ground around the outer edge of the merry-go-round in the opposite direction to its rotation. Still moving, he jumps directly onto the rim of the merry-go-round, bringing it (and himself) to a halt.

How fast was Ryan running when he jumped on?

a.6.3 m/s

b.10 m/s

c.3.1 m/s

d.12 m/s

e.13 m/s