How does Gulliver become a hero in Lilliput?

In "Gulliver's Travels," Gulliver becomes a hero in Lilliput primarily by assisting the inhabitants in capturing the enemy fleet of Blefuscu. This act of bravery and strategic importance solidifies his position as a key figure among the Lilliputians. The navy of Blefuscu poses a significant threat to Lilliput, and Gulliver's ability to physically intervene and thwart this threat dramatically shifts the balance of power in favor of Lilliput. His actions not only demonstrate his physical prowess but also highlight his willingness to aid those who were initially viewed as insignificant due to their small size, ultimately granting him a status of admiration and respect within their society.

The other options, while they present possible scenarios that could lead to heroism, do not align with the central narrative of Gulliver’s contributions during his time in Lilliput. Defeating local monsters is not a subplot within this context, teaching new methods of government does not directly showcase extraordinary valor, and providing medical assistance, while noble, is not the defining act that elevates Gulliver as a hero in this particular instance.