Explanation:

- Option 1: Murder

- Murder involves intent to kill or cause grievous harm.

- A lacked malicious intent; thus, this option isn't applicable.

- Option 2: Culpable homicide not amounting to murder

- This occurs when death is caused without intent to kill but with knowledge that it is likely to cause death.

- A did not have the knowledge that the child would die; their actions were in good faith for the child's safety.

- Option 3: Culpable homicide as an exception to Section 300

- This refers to acts that may typically constitute culpable homicide but are exempt due to specific conditions like self-defense or necessity.

- While A's action might align with this, their intention was purely to save the child.

- Option 4: No offence

- A acted in an emergency, intending to save the child, and lacked any criminal intent or knowledge that the fall would be fatal.