A regression model to predict house price was run based on first floor square footage (X1) and the indicator variable RESERVE (1 if the house is on the nature reserve, 0 if not) . They believe that they need an interaction term. Construct the interaction term variable. O The interaction term is the product of the RESERVE variable and the y-intercept. O The interaction term is the product of the RESERVE variable and the X1 variable. O The interaction term is the sum of the RESERVE variable and the y-intercept. The interaction term is the sum of the RESERVE variable and the X1 variable