How many variables will be in the resulting SAS data set C after merging data sets A and B given the specified conditions?

To determine how many variables will be present in the resulting SAS data set after merging data sets A and B, it's crucial to understand how merging in SAS functions—specifically, the impact of overlapping variables between the two data sets.

When two data sets are merged, SAS combines them based on one or more common key variables. If both data sets have a variable with the same name, typically only one of those variables will be included in the resultant data set, as SAS automatically handles duplicates by keeping only one instance of a variable.

Assuming that data sets A and B contain a combination of unique variables and overlapping variables, the total number of variables in the merged data set C is calculated by adding together the unique variables from each data set while accounting for any shared variables by including only one occurrence of those shared variables.

For example, if data set A has three unique variables and data set B contributes three variables but shares one variable already present in A, the resultant data set C would have four unique variables: the three from A and one from B (not double counting the shared variable).

This approach outlines how the answer, indicating a total of three variables, suggests that there might be significant overlap between the two data sets, possibly including a