Final answer:
Option A 'In other words, the facial expressions and body postures you adopt can actually influence how you feel' is the best thesis statement as it encapsulates the paper's main argument about the impact of body language on our emotions.
Step-by-step explanation:
The thesis is a crucial part of a paper, encapsulating the main argument and direction of the text. Out of the given options, the best thesis statement for Alicia's paper on body language and emotions would be Option A. This statement 'In other words, the facial expressions and body postures you adopt can actually influence how you feel' succinctly summarizes the idea that our own body language can impact our emotional state, which ties together the information on the facial feedback hypothesis, body language, and emotional expression provided in the given references.