Consider an economy with firms selling differentiated products, where the only input to production is labour. Which of the following statements is correct? Select one: O a. Firms make no economic rent. O b. None of the listed answers is correct. O c. Firms choose the level of nominal wage that corresponds to the workers' maximum effort. O d. The more inelastic the demand curve faced by the firm, the higher the markup set by the firm. O e. Workers receive no employment rent