Please help !!! with thorough explanation !!!

For a polynomial p(z) of degree four with real coefficients of the form z^4 + az^3 + bz^2 + cz + d it is given that p(i) = 0 and p(2 + i) = 0.

(a) Find all the roots of p(z).

(b) Write p(z) as the product of two quadratic polynomials with real coefficients.

(c) Calculate a, b, c and d.