SELECT DISTINCT COUNT $($V$\_$CODE$)$ FROM PRODUCT;

SELECT COUNT $($DISTINCT V$\_$CODE$)$ FROM PRODUCT;

a$.$ The difference is in the order of operations.

b$.$ The second command applies the DISTINCT keyword to the V$\_$CODEs before the count is taken so only unique values are counted.

c$.$ The first command executes the Count function to count the number of values in V$\_$CODE including duplicate values, and then the Distinct keyword only allows one count of that value to be displayed.

d$.$ All of these choices are correc