After merging data sets A and B, how many observations will be in the resulting SAS data set C?

To determine the number of observations in the resulting data set C after merging data sets A and B, it's essential to understand how merging operates in SAS. The merge process combines observations from two datasets based on common key variables. This means the number of observations in the resulting dataset depends on:

1. The number of common key values present in both datasets.

2. The type of merge being executed (e.g., a one-to-one merge, a one-to-many merge, or a full outer merge).

If there are no common key values between the two datasets, the resulting dataset might not have any observations. Conversely, if all key values in both datasets match, the result could potentially contain all of those records.

Due to these factors, one cannot definitively ascertain the number of observations in dataset C without additional information about the contents of datasets A and B. Thus, the option indicating that it's impossible to tell how many observations will be in dataset C is the correct response. This reflects the uncertainty inherent in the merging process, which is determined by the specifics of key values shared between the datasets.