Select the most appropriate option to fill in the blank.

The seaside resort of Mamallapuram was an ______ part of China's ancient Silk Route.

integral

The most appropriate option to fill in the blank is integral.

The word "integral" means forming an essential part of something. It is the most appropriate word to use in this context, as it conveys the meaning of Mamallapuram being an essential part of the Silk Route.

The other options are not as appropriate.

• Intentional means done on purpose. This is not the right word to use, as it does not convey the same meaning as "integral."
• Intensive means requiring or using a great deal of energy or effort. This is not the right word to use, as it does not convey the same meaning as "integral."
• Intuitive means based on or resulting from direct perception or understanding. This is not the right word to use, as it does not convey the same meaning as "integral."