Consider a large relational database which stores $5$ attributes for each company employee, i$.$e$.,$ unique corporate ID number, social security number $($SSN$),$ name, date of birth, work division.$$ Which of the following is true:

Group of answer choices

a$)$ A valid superkey is $\{$ID$,$ SSN$,$ division$\}$

b$)$ A valid superkey is $\{$name$,$ date of birth$\}$

c$)$ A valid key is $\{$ID$,$ SSN$\}$

d$)$ None of the above