Answer:
I think it might be C. (Vivien’s pursuit of Lancelot despite his marriage.)
Everyone
done his or her homework.
Explanation:
Everyone is singular and, therefore, require singular verb.

Answer:
Understanding
Explanation:
In simple words, Understanding can be understood as a psychological mechanism in which one is prepared to learn about through use ideas to interact effectively with a conceptual or tangible entity, as in an individual, circumstance, or letter. Understanding is just a relationship between the learner and the understood object.
Thus, from the above we can conclude that the correct option is understanding.