Hi dear I need help with this, which one is the right potion?

You use signal phrases to work quoted text into your writing, providing context, explanation, or other introduction for the quote.Signal phrases contain a name (or text title) and a verb that indicates the quoted writer's stance. Signal phrases can be neutral or function as part of your own argument.Directions: Please answer the following questions.What function is the signal phrase (in bold) serving in the following example?Doyle and Portillo definestress "as an event or environmental stimulus (stressor) that we respond to because we perceive it as challenging or threatening" (sec. 12.1).Source: Pastorino, Ellen E. and Susann M. Doyle-Portillo. What is Psychology?: Foundations, Applications, and Integration.4th ed., e-book, Cengage, 2019.

A; To indicate what purpose the quoted content serves

B; To emphasize the quoted authors' credentials

C; To emphasize the source

D; To offer neutral information