Answer: e. As a sunk cost since the R&D expenditure has no bearing on today's investment decision.
Step-by-step explanation:
Sunk Costs are not to be factored in when making decisions because they have already been incurred and cannot be recovered.
This R&D expense should therefore be treated as a sunk cost because it has already been incurred and expensed and does not contribute to the decision today to embark on the men's after-shave venture.