I think it is option (C).
If the answer is helpful then mark me as brainly.
Power = Work Done / Time taken
Where Work Done is Joules, and Time is in Seconds, Power is in Watts
= 2400 J / 6 seconds
= 400 Watts
The power output is 400 Watts.
E=mgh. 196=5kg*9.81m/s^2*h. So h=196/(5*9.81)=4m
The work done by the machine is equal to the product between the force applied and the distance over which the force is applieds, so in this case:

And the power of the machine is equal to the ratio between the work done by the machine and the time taken: