Thailand shares land borders with Myanmar, Laos, Cambodia and which other country?

The correct answer is Malaysia. Thailand shares land borders with exactly four countries: Myanmar to the west and northwest, Laos to the north and northeast, Cambodia to the east, and Malaysia to the south, where the border runs along the northern part of the Malay Peninsula. This southern border with Malaysia is particularly significant because it separates mainland Southeast Asia from the Malay Peninsula's southern extent, and it passes through Thailand's southern provinces, some of which have a Malay-Muslim majority population, giving the border region a distinct cultural character compared to the rest of Buddhist-majority Thailand. Thailand's total of four land neighbours is a frequently tested static fact, and this question is structured so that the three most plausible-sounding Southeast/South Asian nations are offered as distractors rather than obviously irrelevant countries. Vietnam, option B, lies further east on the Indochinese Peninsula and, despite being close to Laos and Cambodia, does not share a direct land border with Thailand — the two are separated by Laos and Cambodia. Indonesia, option C, is entirely separated from mainland Southeast Asia by sea, being an archipelagic nation, and therefore cannot share any land border with Thailand at all. Bangladesh, option D, lies in South Asia, separated from Thailand by Myanmar and a significant stretch of territory and sea, making it geographically implausible as a bordering nation despite occasional confusion due to both countries' proximity to the Bay of Bengal region. A common exam trap is assuming any Southeast Asian country geographically "nearby" on a small-scale map must share a border, when in fact precise adjacency matters. Revision takeaway: Thailand's four land neighbours, in a clockwise arc, are Myanmar, Laos, Cambodia, and Malaysia — memorising this quartet prevents confusion with non-bordering nations like Vietnam.