The correct answer is option A) Laos, Thailand, and Myanmar.

The Golden Triangle is a region located in Southeast Asia, where the borders of three countries meet - Laos, Thailand, and Myanmar. It is named after the golden opium trade that once flourished in this area. Let's explore each country's involvement in the Golden Triangle in detail:

1. Laos:
Laos is one of the countries that forms the Golden Triangle. It shares its borders with Thailand and Myanmar. The country has been a key player in the illicit drug trade due to its geographical location. The mountainous terrain and dense forests provide suitable conditions for cultivating and smuggling narcotics.

2. Thailand:
Thailand is another country that falls within the Golden Triangle. It shares its borders with Laos, Myanmar, Cambodia, and Malaysia. The region has a long history of opium production and trade. However, Thailand has made significant efforts to combat drug trafficking and has implemented various measures to control and eradicate illicit drug activities.

3. Myanmar:
Myanmar, formerly known as Burma, is the third country that falls within the Golden Triangle. It shares its borders with Thailand, Laos, China, Bangladesh, and India. Myanmar has been a major producer and exporter of illicit drugs, particularly opium and methamphetamine. The remote and inaccessible areas of the country provide suitable conditions for drug production and trafficking.

While these three countries are known for their involvement in the drug trade, it is essential to note that efforts have been made by governments and international organizations to combat drug trafficking and promote alternative livelihoods for local communities.

In conclusion, the countries that fall within the Golden Triangle are Laos, Thailand, and Myanmar. These countries have been historically associated with the production, trade, and trafficking of illicit drugs, particularly opium.