Question

Which set is a subset of every set?

A. {}
B. {0}
C. {1}

Answer 1

I'd say the answer is C

Answer 2

Answer: Choice A. { }

This is the empty set with nothing inside it. Another way to write the empty set is to use the symbol
`\varnothing`

The set { 0 } is not the empty set because 0 is inside it, making it nonempty. A set like {1,2,3} does not contain 0, so there's no way {0} can be a subset.