Each of the following conclusions is based on a relationship between X and Y

Each of the following conclusions is based on a relationship between X and Y that could be spurious. For each one: (i) Identify a plausible control variable, Z. (ii) Briefly describe how Z might be affecting the relationship between X and Y.
A. The level of ice cream sales (X) and crime rate (Y) are strongly related: As sales go up, so does the crime rate. Conclusion: To reduce the crime rate, ice cream should be prohibited.
B. When one looks at the relationship between marital status (X) and party identification (Y), one finds: Married people are more likely to be Republican than people that are not married. Conclusion: Getting married causes people to become Republican.
C. Individuals’ attendance at religious services (X) is related to the number of children they have (Y). Conclusion: Declining religious attendance causes declining birthrates.