Final answer:
The given set {∅,{a},{b},{a,b}} is not the power set of any set.
Step-by-step explanation:
The given set, {∅,{a},{b},{a,b}}, is not the power set of any set. To be a power set, it must contain all possible subsets of a given set. In this case, the set contains the empty set, {∅}, the set {a}, the set {b}, and the set {a,b}, but it is missing the set {a,b} – the two-element set that would complete the power set. Therefore, the answer is No.