Answer Happy

What is the code for the correct answer with justification for the choice?
Faster please
19)Let (X,T) be a topological space having a set A such that: 14 = 28. Int(A)=17, BD(A)| = 30,(Ext(A)| =13 Then |x|= A)30 B) 60 C) 32 D) N.A. 20) Referring to question 19 above, An Bd(A)) = A) 19 B)11 C) 30 D) N.A. 21) Referring to question 19 above, \Bd(X - A)) = A) 19 B) 30 C) 11 D) N.A. 22) Referring to question 19 above, \Bd(A) – A = A) 11 B) 19 C) 30 D) N.A.