Which of the following is true for normal projects if the cost of capital is positive?

a) If a project's IRR is positive, then its NPV will always be positive

b) If a project's NPV is negative, then its Modified IRR will be negative

c) If a project's NPV is positive, then its Profitability Index will always be positive

d) If a project's IRR is positive, then its Discounted Payback Period will exist