Acceleration of train when it is moving steadily from $$$4.0 :ms^{-1}$$$ to $$$20 :ms^{-1}$$$ in 100s is

Acceleration of train when it is moving steadily from $$$4.0 :ms^{-1}$

1.	Acceleration of train when it is moving steadily from $$$4.0 :ms^{-1}$$$ to $$$20 :ms^{-1}$$$ in 100s is
A.	$$$1 :ms^{-2}$$$
B.	$$$2 :ms^{-2}$$$
C.	$$$0.16 :ms^{-2}$$$
D.	$$$3 :ms^{-2}$$$
Answer» D. $$$3 :ms^{-2}$$$