A market research for Pfeizer revealed that the demand for her new painkiller launched next month is perfectly inelastic. If this is true, marginal revenues for the new drug would be:

1) Negative

2) Positive

3) Zero

4) Constant

Pfeizer's CEO didn't believe that market research and asked for a new more extensive one covering all major consuming countries worldwide. She was right as the results revealed a regular demand schedule with a demand elasticity ranging within the [0.8, 2/1] interval. If CEO's objective is to maximize market share getting a dominant market position then at the equilibrium:

1) MR = 0

2) MC = 0

3) MR = MC

4) MR = p