Exp) Option d is the correct answer.

Option a, b and c are incorrect. English is the language which is the official language of a state but is still not recognized in the 8th schedule of the constitution of India. Similarly, Rajasthani language is still not included in the 8th scheduled of the constitution and Rajasthan government is trying to include it into 8th schedule.

Option d is correct. The Eighth Schedule of the Constitution specifies 22 languages (originally 14 languages). These are Assamese, Bengali, Bodo, Dogri (Dongri), Gujarati, Hindi, Kannada, Kashmiri, Konkani, Mathili (Maithili), Malayalam, Manipuri, Marathi, Nepali, Odia, Punjabi, Sanskrit, Santhali, Sindhi, Tamil, Telugu and Urdu. Sindhi was added by the 21st Amendment Act of 1967; Konkani, Manipuri and Nepali were added by the 71st Amendment Act of 1992; and Bodo, Dongri, Maithili and Santhali were added by the 92nd Amendment Act of 2003.