The capital of Cambodia is:

Phnom Penh is the capital and largest city of Cambodia. It lies at the confluence of the Mekong, Tonle Sap and Bassac rivers, in the south-central part of the country.

About Phnom Penh:

• It became the capital in the 15th century, after the decline of Angkor, and again permanently during the French colonial period in the 1860s.
• Important landmarks include the Royal Palace, the Silver Pagoda, Wat Phnom (the hill temple after which the city is named), and the National Museum.

The city was emptied by the Khmer Rouge regime in 1975, when its residents were forced into the countryside. The Tuol Sleng Genocide Museum and the Choeung Ek "Killing Fields" memorial recall the atrocities of that period.

About Cambodia:

• Cambodia is in South-East Asia, bordered by Thailand, Laos and Vietnam, with a coastline on the Gulf of Thailand.
• It is a constitutional monarchy; the king is Norodom Sihamoni.
• The official language is Khmer, and Theravada Buddhism is the main religion.
• The currency is the riel, though the US dollar is widely used.

Angkor Wat:

• Cambodia's most famous monument is Angkor Wat, near Siem Reap, built in the early 12th century by King Suryavarman II of the Khmer Empire.
• It was originally a Hindu temple dedicated to Lord Vishnu, later converted into a Buddhist temple.
• It is the largest religious monument in the world and appears on Cambodia's national flag.
• India has helped restore Angkor Wat and the Ta Prohm temple through the Archaeological Survey of India.

Tonle Sap:

The Tonle Sap lake is the largest freshwater lake in South-East Asia. During the monsoon, the Tonle Sap river reverses its flow, and the lake expands several times in size.

India and Cambodia:

• They share ancient cultural links; Indian influences can be seen in Khmer art, script, language and temples.
• Cambodia is a member of ASEAN and the Mekong-Ganga Cooperation.

Why not the other options?

• ✗Vientiane, Hanoi and Bangkok are the capitals of Laos, Vietnam and Thailand.