Question

To increase power, it is necessary to

decrease the work being done and decrease the time in which the work was completed.

increase the work being done or decrease the time in which the work is completed.

increase the work being done and increase the time in which the work was completed.

decrease the work being done and increase the time in which the work is completed

Answer 1

Think What power is. What's the formula for power?

Answer 2

Or rephrase the question into something that appeals to your day-to-day experiences. If you have two engines, of which the first has much more power than the second, then:

...the first engine can get more/less work done in the same time period than the second engine;

... the first engine can is slower/quicker in getting the same volume of work done than the second engine.

This helps you to figure out which elements constitute 'power' and how they relate to eachother.