Explanation:

- The Indian junior men's skeet team secured a silver medal at the ISSF World Championships in 2018.

- The correct answer is Option 3: South Korea. The event took place in Changwon, South Korea.

- The ISSF (International Shooting Sport Federation) World Championships are global competitive shooting events conducted by the ISSF.

- The Championships include various shooting disciplines, engaging athletes worldwide.

- Option 1: Argentina, Option 2: Hungary, and Option 4: North Korea are incorrect in the context of the 2018 ISSF World Championships location for the Indian junior men's skeet team's performance.

- Each country listed has hosted different international events, but only South Korea was the host in this instance.