The Gandak River originates in:

The correct answer is: b) Nepal.

The Gandak River is a major tributary of the Ganges River. It originates in the Himalayas in Nepal and flows through India before joining the Ganges in Bihar. The Gandak is a major source of irrigation and drinking water for millions of people in Nepal and India. It is also a popular destination for fishing and boating.

The other options are incorrect because:

• Option a) is incorrect because the Gandak River does not originate in India.
• Option c) is incorrect because the Gandak River does not originate in China (Tibet).
• Option d) is incorrect because the Gandak River does not flow through Bangladesh.