Use the Following Information for Questions

Use the following information for questions:
In a report by Reuters, the headline read "Emotional Support Helps Breast Cancer Survival" The headline was based on a study of 847 women (442 black women and 405 white women) with breast cancer and how they fared over a 9-year period. The authors wrote "Women in our study who reported low levels of both emotional expression and emotional support experienced 2 to 4 times greater breast cancer mortality than women reporting high levels of both".
-What was a potential confounding variable?

A) Breast cancer mortality
B) Emotional expression and emotional support
C) Race (black or white)
D) Stage of breast cancer at diagnosis