The correct answer is: C. not a vigilant
The sentence should be: “According to me, the Indians in general are not vigilant and security conscious people.”
The verb “to be” must agree with the subject of the sentence. In this case, the subject is “the Indians in general.” The plural subject requires the plural verb “are.”
The word “vigilant” means “watchful and attentive.” The word “security conscious” means “aware of the need for security.” The sentence is saying that Indians in general are not watchful and attentive, and are not aware of the need for security.
The sentence is grammatically correct, but it is also offensive and stereotypical. It is important to be careful about the language we use, and to avoid making generalizations about entire groups of people.