If you increase your work and decrease your time, you will haveA. more power. less power. the same amount of power. power rating can not be determined

You will have the same amount of power.

One way to look at this is:
If you work for 10hours at a normal rate (which we’ll call one) then 10x1 is 10. Your power is still at 10

If you work for 5 hours, but twice as hard, then you do 5x2 which is ten. The amount of power is always the same

True.it is better to buy a washer with a higher efficiency rating