Question) Which one of these statements is correct?

Multiple choice Answer) Please answer and Explain!

a) Operating cash flow is equal to net income plus depreciation plus taxes. [OCF=NI+Depr+Taxes]

b) Sunk costs should be included in the initial cost of a project.

c) Synergy occurs when a new product reduces the sales of a current product.

d) The cost of test marketing a product prior to deciding whether or not to produce the product is a sunk cost.

e) Real cash flows must be discounted at the nominal rate.