14. A flexible accelerator model can be showed as the equation ，where is net investment, is an adjustment coefficient, and is the desired and the capital stock in the last period, respectively. The capital depreciation equation is  D=0.1K。If the capital stock ，，D₀=4，and  α=0.5. Thus, the gross investment in the period t=3.     
(A) 3
(B) 4.3
(C) 7
(D) 8.3
(E)None of the above.