A . True, this statement will execute successfully. In Oracle SQL, column aliases can be given in double quotes which allows the use of special characters like a hyphen. Additionally, you can perform arithmetic operations such as amount+100 directly in the SELECT clause to return increased values of amount.
C . True, this statement is also valid. It does not use any special characters or reserved keywords as aliases that would require double quotes. The arithmetic operation is the same as in option A, which is permissible.
For B, D, and E, the reasons for failure are: B. In Oracle SQL, single quotes are used for string literals, not for column aliases. Therefore, using single quotes around 'CUSTOMER-ID' and 'DUES' will result in an error. D. The word "DATE" is a reserved keyword in Oracle SQL. When used as a column alias without double quotes, it will lead to an error. In this statement, although "DATE" is in double quotes, it's a best practice to avoid using reserved keywords as aliases. E. There are syntax errors in the statement. "customer id" should be "customer_id", and the alias "CUSTOMER-ID" should be enclosed in double quotes if special characters are used. Also, "DUES AMOUNT" as an alias should be in double quotes to be valid because it contains a space.
Reference:
Oracle documentation on column aliases: Oracle Database SQL Language Reference Oracle reserved words: Oracle Database SQL Language Reserved Words