Explanation:

- The historic meeting between US President Donald Trump and North Korean Leader Kim Jong Un took place on June 12, 2018.

- Option 1: Pyongyang - Pyongyang is the capital of North Korea, but it was not chosen as the meeting location.

- Option 2: Seoul - Seoul, the capital of South Korea, was not selected for this meeting.

- Option 3: Singapore - Singapore was the neutral location where the summit was held. It marked the first-ever meeting between a sitting US president and a North Korean leader.

- Option 4: Taipei - Taipei is the capital of Taiwan and was not considered for this meeting.