Question 1 The constraint primary key means that the values must be: Not yet answered Marked out of 1.00 a. not null O b. unique O c. not null and unique O d. null Flag question Question 2 Based on the data inserted to university database, which of the following is a valid update statement: Not yet answered Marked out of 1.00 a. Update majors set major_id=128 where major_name like 'c%'; O b. Update majors set faculty="Engineering' where major_name like '%engineering%'; c. Update majors set major_name=law where major_id=124; O d. Update majors set major_name='law' and faculty='law where major_name like '%'; Flag question Question 3 During creation of Exam_results table, you can add a constraint that validates the Mark to be valid: Not yet answered Marked out of 1.00 a. Create table Exam_results (Mark number(5,2) check (Mark between 0 and 100)); O b. Create table Exam_results (Mark number(5.2) check (Mark = 100)); O c. Create Exam_results (Mark number(5,2) check Mark>= 0 and Mark 0 and Mark =