Which of the following statements is most correct?

a. One of the key steps in the development of pro forma financial statements is to identify those assets and liabilities which increase spontaneously with net income.

b. The first, and most critical, step in constructing a set of pro forma financial statements is establishing the sales forecast.

c. Pro forma financial statements as discussed in the text are used primarily to assess a firm's historical performance.

d. The capital intensity ratio reflects how rapidly a firm turns over its assets and is the reciprocal of the fixed assets turnover ratio.

e. The constant ratio method produces accurate results when fixed assets are lumpy and when economies of scale are present.