There Are Two Ways to Correct for Projects with Unequal

There are two ways to correct for projects with unequal lives when using the NPV approach.Which of the answers below is one of these ways?

A) One way is to find a common life,without the need to extend the projects to the least common multiple of their lives.
B) One way is to find the present value factors and then compare them.
C) One way is to compare the lengths of the projects and take the project with the shortest life.
D) One way is to find a common life by extending the projects to the least common multiple of their lives.