Francis enjoys spending time with his girlfriend, Carla. Carla will often eat a large number of grilled onions before spending time with Francis. One day, Francis walks by a hot dog stand and smells some fresh grilled onions. Suddenly, Francis has a great desire to see Carla. What is the neutral stimulus (NS) in this scenario?
a. spending time with Carla
b. a hot dog stand
c. grilled onions
d. spending time with Francis