Final answer:
Viola's need to see Olivia's face in 'Twelfth Night' is due to her role as Orsino's messenger, as she navigates her own love for Orsino while trying to woo Olivia on his behalf.
Step-by-step explanation:
The importance of Viola/Cesario needing to see Olivia's face in Shakespeare's 'Twelfth Night' is rooted in Viola's disguised role and her complex feelings towards Orsino. Viola, dressed as Cesario, must assess Olivia for a multitude of reasons, but none of the options provided in the question directly address Viola's predicament in the play. Instead, Viola's need to see Olivia's face stems from her role as a messenger for Orsino, fulfilling her duty to win Olivia's love for him while also harboring her own love for Orsino. This situation leads to a series of comedic and poignant misunderstandings that drive the plot of the play.