We consider the following SQL code: CREATE TABLE Transcript $($ Studld INTEGER, CrsCode CHAR$(6),$ Semester CHAR$(6),$ Grade CHAR$(1),$ PRIMARY KEY $($Studld$,$ CrsCode, Semester$))$ Check all the statements that are true. Studld, CrsCode is a primary key Studld is unique in Transcript There are $3$ primary keys The primary key is composed of $3$ attributes