Three activities are candidates for crashing on a project network for a large computer installation (all are, of course, critical). Activity details are in the following table: \begin{tabular}{cccccc} \hline Activity & Normal Time (days) & Crash Time (days) & Normal Cost & Total Cost with Crashing & Immediate Predecessor(s) \\ \hline A & 7 & 6 & $4,500 & $4,900 & \\ B & 4 & 2 & $1,500 & $3,400 & A \\ C & 11 & 9 & $4,600 & $6,600 & B \\ \hline \end{tabular} a) Activity that should be crashed first to reduce the project duration by 1 day is b) Activity that should be crashed next to reduce the project duration by one additional day is c) Total cost of crashing the project by 2 days =$ (Enter your response as an integer.)