(i) B = {x : x is a natural number smaller than 6}.

B = {, , , , }

(ii) C = {x : x is a two-digit natural number such that the sum of its digits is 8}.

C = {, , , , , , }

(iii) D = {x : x is a prime number which is a divisor of 60}.

D = {, , }

(iv) E = {x : x is an alphabet in BETTER}.

E = {, , , }