Answer:
B. Color theory
Step-by-step explanation:
A color theory can be defined as the science and art that guides people on how to use and combine various colors. Therefore, a good understanding of color theory would help someone to know the relationship (similarities and differences) between various type of colors such as primary colors, tertiary colors and secondary colors.
In this scenario, Krya needs help deciding which colors she should use on her web page. Thus, she should use color theory to help her decide on what color combinations are best for her web design.