Stuck on a finance assignment can anyone give me a hand?

I have to disagree with "Alan" on B. B is false. You could have a negative NPV project that has a shorter than threshold payback period. Negative NPV projects reduce wealth and should NOT be undertaken. (Negative NPV means, among other things, that you are NOT receiving your required rate of return. If you are using an opportunity cost of capital for the required rate of return, other opportunites - other than the negative NPV project - should be undertaken.)

As an example, consider a $100 investment with CF's: 50,50,0,0,0,0,0,0,0,0. (a ten-year project). With a required rate of return of say 9%, your NPV is ($12.04) <parens indicate a negative NPV, even though the payback period is 2 years. Of course, if your only criteria is meeting or beating a time theshold on payback period, then you would accept the project. But using an accounting payback period is a very bad criteria for choosing whether or not to pursue the project (for the reasons stated above).

A & C are true. This occurs, for example, in situations where there are only negative cash flows.

(See "mathematics" section here: http://en.wikipedia.org/wiki/Internal_rate_of_retu...

D. False. The statement here, that is false, is essentially "choose investment A when alternative investment B has a higher IRR"...

A) is correct as in many cases there may not exist an IRR

B) is correct as a corp usually accepts a project if it pays back within a given time frame usually the within the life of the project

C) This is correct as it is same as A) because there may be no rate at which NPV is zero thus no IRR

D) I do not understand the wording of this. Yet acceptance criteria for IRR states to accept a project if its rate of return is higher than cost of capital (opportunity cost) and higher the rate better returns from it