Which of the Following Methods Utilizes Discounted Cash Flows When

Multiple Choice

Which of the following methods utilizes discounted cash flows when analyzing potential capital expenditures?
Methods:
1) Accrual accounting rate-of-return
2) Internal Rate of Return (IRR)
3) Payback Period
4) Net Present Value (NPV)

A) 1 only
B) 1 and 2
C) 1 and 3
D) 2 and 4