Which three statements are true regarding single-row functions? (Choose three.)
A.
They can return multiple values of more than one data type.
B.
They can be used in SELECT, WHERE, and ORDER BY clauses.
C.
They can accept a column name, expression, variable name, or a user-supplied constant
as arguments.
D.
They can accept only one argument.
E.
They can be nested up to only two levels.
F.
They can modify the data type of the argument that is referenced.
B, C, F
Why B is correct? How it can be used in ORDER BY?
Single-row functions return a single result row for every row of a queried table or view. These functions can appear in select lists, WHERE clauses, START WITH and CONNECT BY clauses, and HAVING clauses.
https://docs.oracle.com/database/121/SQLRF/functions002.htm#SQLRF20032