Final answer:
The subject of this question is Mathematics. If two lines intersect, then they will intersect at exactly one point is a postulate in geometry. The postulate can be visually demonstrated through a geometric diagram.
Step-by-step explanation:
The subject of this question is Mathematics, and it pertains to the idea of lines and their intersections.
The correct answer to this question is C) Postulates. Postulates are statements that are accepted without proof, and the statement 'If two lines intersect, then they will intersect at exactly one point' is a postulate in geometry.
This postulate can be illustrated through a geometric diagram, showing two lines intersecting at a single point, and no other points of intersection.
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