Explanation:

Gymnosperms and angiosperms are spermatophytes i.e. trees that bear seeds. In Gymnosperms, there is no flowering and the seed is present in an unclosed condition. Whereas angiosperms are the flowering plants in which the ovule of the plant develops into a seed which is present inside the fruit which is part of a ripened ovary. Therefore, A and B are correct statements. In India there are no large parrots found. There are only parakeets and hence statement D is also correct. The only incorrect statement is C.

Primary pollutants are the pollutants which harm the environment in the form they are added to it. NOx or oxides of Nitrogen are harmful in their existent form and hence classify to be a primary pollutant. Hence both the statements are correct and answer is C.