Final answer:
The question lacks necessary information such as expected sales figures and their probabilities to compute the expected value of total sales projections. Consequently, it's impossible to determine the correct answer choice without complete data.
Option 'C' is the correct.
Step-by-step explanation:
The question provided is incomplete as it does not include the necessary information such as the number of prefabricated buildings expected to be sold in various states of the economy or the associated probabilities.
To calculate the expected value of total sales projections, we need a complete set of outcomes (sales figures) and their corresponding probabilities. The expected value is determined by multiplying each outcome by its probability and summing the products. The formula is:
Expected Value (E) = Σ (probability of outcome x outcome value)
Without the specific data, we cannot compute the expected value, and therefore cannot determine which answer choice is correct. The details given about economies of scale or the present value of future cash flows are unrelated to the calculation of expected value for sales projections.