The correct answer is option 4, Tropical dry deciduous forest. This type of forest is the most widespread in India.

Let`s analyze each option to better understand why option 4 is the correct answer:

Option 1, Tropical wet evergreen forest, is a type of forest found in areas with high rainfall throughout the year, such as the Western Ghats region. While these forests are important and exist in India, they are not the most widespread type.

Option 2, Thorn-scrub forest, is a type of forest found in arid and semi-arid regions like Rajasthan. However, they are not as widespread compared to the Tropical dry deciduous forest.

Option 3, Mangrove forest, is a type of forest found in the coastal regions with saline or brackish water. They are important ecosystems, but they are not as widespread as the Tropical dry deciduous forest.

Option 4, Tropical dry deciduous forest, is the correct answer because it is the most widespread type of forest in India. These forests are found in areas with distinct wet and dry seasons, like central India. They are characterized by trees that shed their leaves during the dry season.

In conclusion, option 4, Tropical dry deciduous forest, is the most widespread