Q56·Section II (Mathematics)·56 of 180Topology — normality via shrinking neighbourhoodsA topological space X is normal if: OptionsAX is T2T_2T2BX is regular and T2T_2T2Cfor given x∈Xx\in Xx∈X and a neighbourhood uuu of xxx there exists an open set vvv such that x∈vˉ⊂ux\in\bar v\subset ux∈vˉ⊂uDfor a given closed set A⊂XA\subset XA⊂X and an open set uuu containing A, there is an open set V such that A⊂Vˉ⊂uA\subset\bar V\subset uA⊂Vˉ⊂uPick an option to check your answer.Show answerShow solution Report a problem with this question← Q55All questionsQ57 →Keyboard: A–D answer · S solution · ←/→ previous/next