Question

Which combination of fundamental units can be
used to express the amount of work done on an
object?
(1) kg•m/s (3) kg•m^2/s^2
(2) kg•m/s^2 (4) kg•m^2/s^3

Answer 1

     The work spent during a move is given by the Definition of Word:

$T=F\Delta S \\ T=ma\Delta S$
 
     Analizyng the units, we have:

$J=kg* \frac{m}{s^2} *m \\ \boxed {J= \frac{kg*m^2}{s^2} }$

Number 3

If you notice any mistake in my english, please let me know, because i am not native.