The correct answer is (a) 121 A.
Section 121 A of the Indian Penal Code defines sedition as an attempt to excite disaffection towards the government established by law in India. It also includes words, signs, and visible representations that bring or attempt to bring into hatred or contempt, or excite disaffection towards the government established by law in India.
Section 122 A of the Indian Penal Code deals with the offence of waging war against the government of India. Section 123 A of the Indian Penal Code deals with the offence of abetting the waging of war against the government of India. Section 124 A of the Indian Penal Code deals with the offence of sedition.
Sedition is a serious offence and can be punishable with imprisonment for life or with imprisonment for a term which may extend to three years, or with fine, or with both.