As Other Countries Grow Wealthier, the Incentive to Undertake Research

As other countries grow wealthier, the incentive to undertake research and development projects:

A) increases, since the potential for profits rises.
B) decreases, since competition drives profits lower.
C) decreases, since the marginal returns to R&D fall when more countries are wealthier.
D) increases, since there is more government subsidization when countries are wealthier.