Common nouns are words that name general people, places, things and ideas whereas proper nouns name a specific person, place, or thing. For example, 'country' is a common noun and 'India' is a proper noun. The first letter of a proper noun is capitalized. From the given options, Option B is correct because Portuguese and India are proper nouns that name a group of people of a specific nationality and country, respectively. Option A is incorrect because Portuguese and India are both proper nouns, not common nouns. Portuguese is a proper noun that refers to people from a specific country, Portugal and India names a specific country. Option C is incorrect because India is a proper noun that names a specific country. Option D is incorrect because Portuguese is not a common noun, it's a proper noun that refers to citizens of the country Portugal.