A psychologist examined the impact of color on the attention of online consumers. Twenty$-$four shoppers are recruited to participate and assigned to two groups. Group $1(n=12)$ participants are directed to a shopping website with a white background on the main content page. Group $)=(12$ participants are directed the same shopping website but the main content page has been altered and now the background color is a pale lilac. The number of seconds consumer participants spend on the main content page were recorded.

Identify the independent variable for the study.

Consumer concentration

Color of main web page

Number of seconds spent looking at a webpage

Consumer behavior