The correct options are
A If a bill falls due on a date which is not existent in that month, last day of month is taken.
B If the bill becomes legally due on a Sunday or a public or gazette holiday, the (legally) due date is supposed to be one day earlier.
C If the date on which the bill is legally due is declared as an emergency holiday, the bill can be paid one day later.
For calculating the due date, following points are important :-
⇒ If a bill falls due on a date which is not existent in that month, last day of month is taken.
⇒ If the bill becomes legally due on a Sunday or a public or gazette holiday, the (legally) due date is supposed to be one day earlier.
⇒ If the date on which the bill is legally due is declared as an emergency holiday, the bill can be paid one day later.