a$.$ Write down the decision sub$-$tree for stage n$,$ given that sn $>=6,000$ and we invest in Fund B$.$

b$.$ Complete stage $3,$ stage $2$ and stage $1$ tables.

c$.$ Provide the OPTIMAL SOLUTION in terms of maximum expected amount of money at the end of year $3$ and the optimal decision for every possible state in years $1,2,$ and $3,$ including the function

arguments and values.