FICA excludes from coverage all of the following kinds of employment except:

a$.$ federal government secretaries hired in $1990.$

b$.$ babysitting service performed by a $35-$year$-$old person who receives $$40$ in cash during the calendar quarter.

c$.$ service performed by a $16-$year$-$old child in the employ of the mother.

d$.$ domestic service performed in a college sorority by a student.

e$.$ services performed by a railroad worker for an employer covered by the Railroad Retirement Tax Act.