Let g(x)=x3+kx2−4kx−4k, where k is a non-zero integer.
a. (i) Given that x=2 is a zero of g(x), find the value of k.
b. (ii) For the value of k obtained in part (i), factorise g(x) completely.
c. (iii) Write all the zeros of g(x) for this value of k.