A cricket ball of mass 150 g collides straight with a bat with a velocity of $10 \mathrm{~ms}^{-1}$. Batsman hits it straight back with a velocity of $20 \mathrm{~ms}^{-1}$, If ball remains in contact with bat for $0.18$, then average force exerted by the bat on the ball is
(a) $15 \mathrm{~N}$
(b) $45 \mathrm{~N}$
(c) $150 \mathrm{~N}$
(d) $4.5 \mathrm{~N}$