However, it can be inferred from the given options that Vivian might say she is a savage because she believes that her behavior is less than ladylike. The use of the word "savage" implies a lack of refinement or civility, and if Vivian sees her behavior as not being "ladylike," she may feel that she is not conforming to societal expectations of feminine behavior.
It is also possible that Vivian's statement is meant to be ironic or humorous, as the juxtaposition of the words "savage" and "King Arthur socks" is unexpected and playful. The play may be using Vivian's statement to comment on the arbitrary nature of societal norms and expectations.
Again, without more information or context, it is difficult to say for certain why Vivian says she is a savage in King Arthur socks in the play.