1. Lion-tailed Macaque: This species is primarily diurnal, meaning it is active during the day and rests at night. They are known for their distinctive mane and tail tuft, and they inhabit the rainforests of the Western Ghats in India.
2. Malabar Civet: The Malabar Civet is generally nocturnal. It is most active during the night and is rarely seen during the day. It is a critically endangered species native to the Western Ghats and nearby regions.
3. Sambar Deer: The Sambar Deer is largely nocturnal or crepuscular (active during twilight). It tends to be most active during the early morning and late evening but can also be seen foraging at night.

Given this information, two of the listed fauna (Malabar Civet and Sambar Deer) are generally nocturnal or most active after sunset. Therefore, the correct answer is: Only two.

Let’s analyze the statements:

Statement-I: Marsupials are not naturally found in India. This statement is correct. Marsupials, such as kangaroos and koalas, are primarily found in Australia and nearby islands. They are not native to India.

Statement-II: Marsupials can thrive only in montane grasslands with no predators. This statement is incorrect. Marsupials inhabit a wide variety of environments, including forests, grasslands, and deserts. They are not limited to montane grasslands and can coexist with predators, as evidenced by their presence in diverse habitats in Australia, where they have adapted to various ecological niches.

Therefore, the correct answer is: Statement-I is correct but Statement-II is incorrect.

The Congo Basin is a large, tropical rainforest region in central Africa that spans across several countries. The main countries that make up the Congo Basin are:

1. Democratic Republic of the Congo (DRC) – It holds the largest portion of the Congo Basin and is home to a significant part of the rainforest.
2. Republic of the Congo – Also known as Congo-Brazzaville, this country has a substantial portion of the Congo rainforest.
3. Central African Republic – Located to the north of the Congo Basin, it contains part of the rainforest region.
4. Gabon – Although it has a smaller share, Gabon has a well-preserved part of the Congo Basin rainforest.
5. Cameroon – The southern part of Cameroon is part of the Congo Basin.
6. Equatorial Guinea – The mainland region of Equatorial Guinea (Río Muni) is included in the Congo Basin.

These countries collectively make up the Congo Basin region, which is the second-largest tropical rainforest in the world, after the Amazon. It is known for its rich biodiversity, complex ecosystems, and significant role in regulating the Earth’s climate. So, Cameroon is the correct answer.

India possesses substantial reserves of heavy minerals predominantly located along its coastal regions and in inland placer deposits. These heavy mineral sands include a collection of seven key minerals: ilmenite, leucoxene (also known as brown ilmenite), rutile, zircon, sillimanite, garnet, and monazite. Among these, ilmenite (FeO.TiO₂) and rutile (TiO₂) are the principal sources of titanium. Titanium dioxide is found in various polymorphic forms, namely rutile, anatase (octahedrite), and brookite. The correct answer is: Titanium.