Answer: "a given"and"property of algebra" can be used as a reason in a two- column proof.
Explanation:
A two-column proof is consist of two columns ,one is for statement and the other is for the reasons for the statement. It is a very common way to arrange the proof in order to understand. Reasons can be definitions, postulates, properties ,given,previously proven theorems.(a given is only used as reason for any statement if it is a given in that particular problem).