Question

A ⊆ B means: A is an element of B B is a subset of A B is an element of B A is a subset of B A is a subset of B and B is a subset of A

Answer 1

A is a subset of B

Answer 2

The symbol
`\subset` stands for subset. So,
`A \subset B` means that A is a subset of B.

This means that every element in A is also an element of B, while the opposite is not necessarily true: there can be elements of B that are not elements of A.

For example, if you consider the sets

`A = \{ \text{US Capitals} \},\ \ B = \{ \text{US Cities} \}`

You can see that A is a subset of B: every Capitol is a city, but most cities aren't capitols.