Explanation:

- Option 1: Section 440 Cr. P.C.

- Deals with the amount of bond and reduction thereof in criminal cases.

- Does not pertain to the discharge of sureties.

- Option 2: Section 345 Cr. P.C.

- Relates to the procedure in cases of abatement of nuisance.

- Unrelated to surety discharge.

- Option 3: Section 323 Cr. P.C.

- Concerns cases being transferred to the Court of Session.

- Not about sureties or their discharge.

- Option 4: Section 444 Cr. P.C.

- Deals with the discharge of sureties in a bond.

- Correct section regarding the discharge process.