Using an incremental internal rate of return (IRR) analysis, the decision to replace the "current best" by the "challenger"' is based on what decision rule?

a. The internal rate of return of the increment is greater than the external rate of return.

b. The increment's internal rate of return is greater than the previous increment's internal rate of return.

c. The increment's internal rate of return is greater than 0 .

d. The increment's internal rate of return is greater than MARR.