Convert each signal to the finite sequence form {a, b, c, d, e}. \text { (a) } u[n]-u[n-4] \text { (b) } u[n]-2 u[n-2]+u[n-4] \text { (c) } n u[n]-2(n-2)

u[n-2]+(n-4) u[n-4] \text { (d) } n u[n]-2(n-1) u[n-1]+2(n-3) u[n-3]-(n-4) u[n-4]