pls help soon

A factory produces chemical K and effluent E which it dumps into the river. It affects the downstream firm which produces fish F. The two firms are competitive and face unit price PK=10 and PF= 20 for the chemical and fish respectively. The cost function of the chemical factory is C (K, E) = K2 (5-E) +1 while the cost function of the fishery is C( F, E) = FE. If both the firms choose the level of output that maximizes their profit, then what would be the optimal value of K, E, and F? (a) (5, 0, 5/8) (b) (3, 0, 2/5) (c) (5, 5, 2/5) (d) (5. 5, 5/8)