The command "ALTER TABLE guests' CHANGE 'fname 'firstname will Select one: O a. Change the field name for the field 'fname O b. Change the first name of all users in the database OcAffect only guests with first names od Produce an error Which of the following can be used as a primary key? Select one: Date of Birth, along with place of birth ob. National Identification Number O a Oc Major O d. Grade Point Average