Evidence in an argument that consists of reason that claim that the particular argument is true.
Explanation:
In order to prove a fact is true we need to have the appropriate evidence.
For example:
If we say that the earth is round then we need to have sufficient data /reasons to prove the claim (i.e. earth is round) to be true
Another example is that if we claim that sun is the planet that provides us sunlight then we need to have proper evidence in place that prove that this fact is true.
Considering other option given in question like
So we can say that Evidence in an argument consists of reason the claim is true.