A set is a well-defined collection of objects. Each object in a set is called an element of the set. Two sets are equal if they have exactly the same elements in them.
A set is a subset of another set if all elements of the set are elements of the set . In other words, the set is contained inside the set . The subset relationship is denoted as A ⊂ B .The relationship of one set being a subset of another is also called inclusion or we can say Set B may have more elements than A does.
Option 4 .Set B may have more elements than A does is the right answer.