how do you say To whom It May Concern in French?

Answer 1

probably
Mesdames, Messieurs

(To whom it may concern is bad business practice in English. Either find out to whom to address your letter--call the business and ask the receptionist or use dear Sir or Madam:)

Answer 2

A qui il peut intéressée

Answer 3

A que Lui l'Inquiétude de mai

Answer 4

à qui de droit