A table VEHICLEOWNERS already exists with all relevant columns but no primary keys. Which of the following SQL will correctly create a primary key which is composite of 3 columns: VIN, driverLicense, and regDate Selected Answers: ALTER TABLE VEHICLEOWNERS ADD CONSTRAINT PK1 PRIMARY KEY (VIN) , PRIMARY KEY (driverLicense) , PRIMARY KEY (regDate) A table named AIRPLANES already exists with columns as shown above. (note: column names in bold are NOT NULL) Which of the following SQL will successfully change the following 2 columns: 1. manufacturer which needs to be changed to varchar(50) and data is always required; and 2. variant for which data type does not need change but data is not always required