Question

Select the postulate that states points A and B lie in only one line.

Postulate 1: A line contains at least two points.
Postulate 1a: A plane contains at least three points not all on one line.
Postulate 1b: Space contains at least four points not all on one plane.
Postulate 2: Through any two different points, exactly one line exists.
Postulate 3: Through any three points that are not one line, exactly one plane exists.
Postulate 4: If two points lie in a plane, the line containing them lies in that plane.
Postulate 5: If two planes intersect, then their intersection is a line.

Answer 1

pretty sure it's postulate 2

Answer 2

The postulate that states points A and B lie in only one line is:

Postulate 2: Through any two different points, exactly one line exists.

Explanation:

Postulate--

A postulate is a statement that is assumed to be trivially true i.e. it does not require any proof. It is a valid statement that is used to prove some other statements or theorems.It is also known as a axiom.

Among the given postulates the postulate which states that two points A and B will lie in only one line is:

Postulate 2