need help with a and b

This question assumes the following relational schemas in the context of Kafka University: Student StuID, Lname, Fname, Address, DOB, Phone, MajorID, DeptID) Primary Key: StuID Foreign key: MajorID refers to MajorID in Major Major (MajorID, MajorDesc) Primary Key: MajorID You have been given the following PL/SQL block: V DOB Student.DOB/Type; V-SID Student. StuIDType; BEGIN V-DOB :=&StudentDOB; SELECT StuID INTO V_SID FROM Student WHERE DOBV_DOB; END (a) (2 marks) Name the two different types of variables that have been used in the above PL/SQL block. Describe these variable types with one characteristic each (b) (2 marks) Discuss all the error conditions that you may come across as a result of the execution of this anonymous block. Add an appropriate exception handling section to the block in order to handle such errors