(b) (4 marks) Suppose NBN sets the access fee at PN = $45. Assume that each telco only considers setting the monthly subscription fee at one of the following three values: $60, $65, and $70. Construct a 3x3 payoff matrix for the pricing game between Telstra and Optus and find the Nash equilibrium of the game. Calculate each telco's profits, number of subscribers, and the Herfindahl Index (based on the number of subscribers) in equilibrium. (c) (4 marks) Suppose NBN increases Py from $45 to $55. Other things remain the same. Redo (b). It is reported that the average wholesale price for the NBN 50 plan is $45 in 2020. Given NBN's monopoly position in the wholesale market and its goal to meet budget requirements imposed by the government to recover the cost of deploying the non access network infrastructure, NBN is aggressively adjusting its wholesale pricing model over time to meet its targeted average revenue per user. In June 2021, NBN submitted a special access undertaking (SAU) variation to the ACCC for approval. In the SAU, NBN proposes the following three wholesale pricing constructs to be considered by the ACCC (p.10)