The payoff matrix supplied shows outcomes of various strategies that two firms might follow in response to action on the part of the other company. This payoff matrix describes actions in developing vaccines for not-too-rare but also not-too-common diseases. Each element shows the payoffs to a set of strategies as the payoff to Firm A, then a comma, then the payoff to Firm B. Firm B Enter Not Enter Enter -17,-17 155,0 Firm A Not 0,155 0,0 Enter Suppose Firm A is a US company and Firm B is a foreign company. What is the minimum subsidy the US must offer Firm A to ensure that Firm A will choose to produce the vaccine