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An indirect proof is a proof wherein you begin by assuming temporarily that the desired conclusion is not true which then by reasoning logically reaches to a certain contradiction or some other known fact.

1. Assume temporarily that the conclusion is not true.

2. Reason logically until you reach a contradiction.

3. Point out that the assumption was wrong and the conclusion must then be true.

Consider the following statement: If $AB=AC$, then $螖ABD鈮�螖ACD$.

An indirect proof is to be used to prove this statement.

Consider the following statements:

1. Assume temporarily that $AB鈮�AC$
2. Assume temporarily that $螖ABD\cancel{鈮�}ACD$

Write out which of the above statements is the correct way to begin the proof.

Hence, the correct answer is option b.