Under a factor$-$based return attribution approach using the Carhart model, how is the contribution to active return of a specific factor $($e$.$g$.,$ momentum$)$ attributed?

Group of answer choices

Take the difference between the portfolio and benchmark betas for the factor and multiply by the factor's historical excess return.

Multiply the portfolio$$s beta for the factor by the benchmark$$s return.

Subtract the benchmark$$s return from the portfolio$$s return for that factor.