The correct option is C A∈B
A⊆B is true because equal sets are subsets of each other.
B⊆A is also true because equal sets are subsets of each other.
Let set A={a,b,c} and set B={a,b,c} [A and B are equal sets]
a∈B, b∈B, c∈B
But {a,b,c}∉B
⟹A∉B
It means A is a subset of B, but A is not an element of B.
So, A∈B is not true.
Let set A={a,b,c} and set B={a,b,c} [A and B are equal sets]
a∈A, b∈A, c∈A
But {a,b,c}∉A
⟹B∉A which is true.