Section 120. When persons secondarily liable on, discharged - Negotiable Instruments Law

(a) By any act which discharges the instrument;

(b) By the intentional cancellation of his signature by the holder;

(c) By the discharge of a prior party;

(d) By a valid tender of payment made by a prior party;

(c) By a release of the principal debtor, unless the holder's right of recourse against the party secondarily liable is expressly reserved;

(f) By any agreement binding upon the holder to extend the time of payment, or to postpone the holder's right to enforce the instrument, unless made with the assent of the party secondarily liable, or unless the right of recourse against such party is expressly reserved.