'The expression 'to lead a Spartan life' means:

to lead an ascetic life

The correct answer is Option (3) → to lead an ascetic life

The expression "to lead a Spartan life" refers to a lifestyle that is simple, disciplined, and without luxury or indulgence. It originates from the ancient Spartans, who were known for their strict discipline, self-denial, and minimalistic way of living.

OTHER OPTIONS

 To lead a warrior's life – While Spartans were warriors, the phrase refers to their simple lifestyle, not just their warrior skills.
  To lead an army man's life – Army life involves discipline, but it is not necessarily ascetic or minimalistic.
  To lead a healthy life – A Spartan life is strict and simple, but it does not specifically mean "healthy."