Q$3(10)$: Let's say we would like to override equals$()$ method of a Student class. Two students are considered equal if they have same last name and date of birth. Would it be ok to override the hashCode$()$ method such that it returns an integer using:

a$.$ Student ID only

b$.$ Student Last Name $+$ birthdate

c$.$ Student birthdate only

Please briefly explain each part and provide your reasoning?