Castiel Is a Psychologist Who Is Interested in Seeing How

Multiple Choice

Castiel is a psychologist who is interested in seeing how autonomic nervous system responses are related to subjective feelings of fear. Half the participants in Castiel's experiment watch a 10-minute graphic and violent video and the other half watch a 10-minute video of a baby kitten. While the participants are watching the video, Castiel gathers measurements of their skin conductance. After they finish watching the video the participants answer a questionnaire about their level of fear after watching the video as well as how they generally react to horror movies.
-In Castiel's experiment what is the independent variable

A) The participants' skin conductance.
B) The video the participants watched.
C) The participants' general attitude towards horror movies.
D) The participants' sex.