Assertion. A GROUP BY query can also include functions.

Reason. ALL SQL functions can be used in a GROUP BY query.

(c)

Assertion is true but Reason is false.

Explanation
A GROUP BY query can include functions. This is true because SQL allows the use of aggregate functions like COUNT(), SUM(), etc., within a GROUP BY query to perform calculations on grouped data. However, it's important to note that not all SQL functions can be used within a GROUP BY query. Only aggregate functions or functions that operate on grouped data can be used effectively in this context.