In the given case, refer to the News Story 12: "Working nights may increase breast cancer risk". Identify which of the "Reasons for Relationships between Variables" described in Section 11.3 are likely to apply. (Select all that apply.) Reason 1: "The explanatory variable is the direct cause of the response variable." It is possible that working nights was the cause of the cancer in these cases. Reason 2: "The response variable is causing a change in the explanatory variable." Perhaps women with higher risk for breast cancer take night jobs more often. Reason 3: "The explanatory variable is a contributing, but not sole, cause of the response variable." Working nights may increase the risk for breast cancer. Reason 4: "Confounding variables." Confounding variables may include family status, for instance the age at which a woman had children, diet, exercise, and so on Reason 5: "Both variables result from a common cause." Perhaps lifestyle factors such as diet and exercise increase cancer risk and tendency to take night work. Reason 6: "Both variables are changing over time." It may be becoming more acceptable for women to work nights and cancer incidence is also increasing. Reason 7: "The association may be nothing more than coincidence." It is unlikely that working nights is a risk factor.