Geometry

Question Analysis:
This question asks about forming a contrapositive of a conditional geometry statement.
The main focus is on understanding logical equivalence and statement negation.

Key Concept Explanation:
The contrapositive of an "If p, then q" statement is "If not q, then not p".
This form is logically equivalent to the original and is a valid tool in indirect proof.

Step-by-Step Solution:
Original statement:
If lines l and m are parallel (p), then corresponding angles formed by a transversal are congruent (q).
Contrapositive:
If corresponding angles formed by a transversal are not congruent (¬q), then lines l and m are not parallel (¬p).
This new statement can be used to disprove parallelism via angle measurement.

Option Analysis:
✅ A. Correct: flips and negates both terms properly.
B. Inverse — ...