If x = at + bt^2 , where x is the distance travelled by the body in kilometer while t is the time in second, then the unit of b is

If x = at + bt^2 , where x is the distance travelled by the body in ki

1.	If x = at + bt^2 , where x is the distance travelled by the body in kilometer while t is the time in second, then the unit of b is
Answer» `km//s` `km-s` `km//s^(2)` `km-s^(2)` ANSWER :C