The correct answer is (a) State Governments.
The Constitution of India gives the power to levy agricultural income tax to the State Governments. This is because agriculture is a state subject. The Central Government can only levy taxes on income from sources other than agriculture.
The Constitution of India, in Article 246, lists the subjects on which the Parliament and the State Legislatures can make laws. The subjects that are listed in the State List are those that are of a local or regional nature. Agriculture is one of the subjects that is listed in the State List. This means that the State Governments have the exclusive power to make laws on agriculture.
The Central Government can only make laws on agriculture if it is given the power to do so by the Parliament. The Parliament can give the Central Government the power to make laws on agriculture by passing a law under Article 248. However, the Parliament has not yet passed any such law.
As a result, the State Governments have the exclusive power to levy agricultural income tax. The Central Government cannot levy agricultural income tax.