Use the Equation for the Question(s)below

Use the equation for the question(s) below.Consider the following regression model:
Rs - rf = as + (RF1 - rf) + (RF2 - rf) + ε_s
-The term as is a(n) :

A) error term that has an expectation of zero and is uncorrelated with either factor.
B) measure of the expected percent change in the excess return of a security for a 1% change in the excess return of the first factor portfolio.
C) measure of the expected percent change in the excess return of a security for a 1% change in the excess return of the second factor portfolio.
D) constant term.