Which of the following SQL statements isn’t valid? a. SELECT address || city || state || zip "Address" FROM customers WHERE lastname ¼ 'SMITH'; b. SELECT * FROM publisher ORDER BY contact; c. SELECT...

Which of the following SQL statements isn’t valid?

a. SELECT address || city || state || zip "Address" FROM customers

WHERE lastname ¼ 'SMITH';

b. SELECT * FROM publisher ORDER BY contact;

c. SELECT address, city, state, zip FROM customers

WHERE lastname ¼ "SMITH";

d. All the above statements are valid and return the expected results.