To answer this question, let's go through each option to understand why it is correct or incorrect:
A. WHERE address is missing - This option is incorrect because the keyword "missing" in PROC SQL is used to check for missing numeric values, not missing character values. Therefore, it will not list rows that have no data in the Address column.
B. WHERE address not exists - This option is incorrect because the keyword "not exists" is used in SQL to check for the existence of a specific value or condition in a subquery, not to check for missing data in a column.
C. WHERE address is null - This option is correct. The keyword "is null" is used in SQL to check for missing data in a column. It will list rows that have no data in the Address column.
D. both a and c - This option is correct. Both "WHERE address is missing" and "WHERE address is null" will list rows that have no data in the Address column.
Therefore, the correct answer is D. This option is correct because both "WHERE address is missing" and "WHERE address is null" can be used to list rows that have no data in the Address column.