The correct answer is: B. 4 years
The normal term of a State Legislature Assembly is 4 years. This is as per Article 172 of the Constitution of India. The term of the Assembly can be extended by a period not exceeding one year at a time by the Governor on the recommendation of the Council of Ministers. The Assembly can also be dissolved earlier by the Governor on the advice of the Council of Ministers.
Option A is incorrect because the normal term of a State Legislature Assembly is 4 years, not 3 years.
Option C is incorrect because the normal term of a State Legislature Assembly is 4 years, not 6 years.
Option D is incorrect because the normal term of a State Legislature Assembly is 4 years, not 5 years.