Please do part b.

Below is figure (2.4.5)

4. For each countable set of infinite sequences, use diagonalization (2.4.5) to construct an infinite sequence of the same type that is not in the set. a. [(fn (0), fn(1),... , fn(n),...)lf n(k) E (hello, world for n, k e N. b. [(f(n, 0), f(n, 1), ., f(n, n), ...)lf(n, k)Ea, b, c for n k EN. ffano, an1,. .., ann, ank E 2, 4, 6, 8) for n, k E N)