A Researcher Wanted to Examine Whether People Remembered Information Better

A researcher wanted to examine whether people remembered information better with auditory cues or with visual cues. Ten participants were randomly assigned to each of the two groups: one group heard a list of words from headphones, and the other group saw the same list of words from a screen. The participants were then asked to write down as many words as they could remember. The dependent variable was the number of words remembered.
-For which of the following situations is it appropriate to use ANCOVA?

A) In each group, half of the participants had a time limit to write the words down. Whether a time limit was imposed was also included in the model.
B) The participants' socioeconomic status (low, middle, or high) was expected to have an effect on their performance and was also included in the model.
C) Participants took a vocabulary test before the experiment and the scores of the test were included in the model.
D) Participants took a vocabulary test after the experiment and the scores of the test were included in the model.