Answer:
A state of aggravation
Step-by-step explanation:
Looking at the surrounding information of the word "vexation", or context clues, we can infer that "vexation" has a very negative connotation: Alice was about to cry at having lost a person she appreaciated! so we can discard option 1 and 3.
And since the clues in the text are not enough, our best option is to look the word in the dictionary. Vexation refers to a state of being worried, frustrated, annoyed or troubled, similar to the noun "aggravation" which refers to a state of annoyance, exasperation or exacerbation or the process of making a problem, bad situation, or negative feeling worse, such as the bad circumstance of the "dear little fellow-traveler" leaving.