Question $9$

COURSE

subj code

course number

course name

course description

credits

For the COURSE entity, the following is known about its attributes $($none of which are NULL$)$:

subj code is common for multiple courses $($for e$.$g$.$ there are many courses with subj code MIS$)$

course numbers are only unique for a given subj code $($for e$.$g$.$ there can be only one MIS $310$ and only one ACCT $310)$

no two courses can share course names to avoid confusion

course descriptions are always unique

credits for courses are allowed to be only one the following values: $1,1\mathrm{.}5,2,3,6$

Based on the above information, select all choices that qualify as candidate keys.

course number

subj code and course number together

course description

subj code

credits

course name