The Montague-Chelmsford Proposals were related to Option 4: constitutional reforms. These proposals were a set of recommendations made by the British government in 1918 for constitutional reforms in British India, which aimed to grant more self-governance to Indians while retaining British control.

The Montague-Chelmsford Proposals were also known as the Government of India Act of 1919, and they represented a significant step towards granting greater autonomy to Indians in the governance of their country. The proposals were introduced by Edwin Montague, the Secretary of State for India, and Lord Chelmsford, the then Viceroy of India, in response to growing demands from Indian leaders for more participation in the governance of their country.

The proposals included several key constitutional reforms:

1. Introduction of Diarchy: The Montague-Chelmsford Proposals introduced the concept of diarchy, which divided the powers of the provincial government in India into two categories: reserved subjects and transferred subjects. The reserved subjects, such as defense, foreign affairs, and finance, remained under the control of the British government, while the transferred subjects, such as education, public health, and local government, were to be controlled by elected Indian ministers. This marked a significant shift towards Indian self-governance in certain areas.

2. Expansion of the Legislative Councils: The proposals also aimed to expand the Legislative Councils at both the provincial and central levels, and to increase the representation of Indians in these councils. The majority of members in the provincial councils were to be elected, and the central council was to include a larger number of elected representatives. This was seen as a step towards increasing Indian participation in the decision-making process.

3. Reforms in the Provincial Autonomy: The Montague-Chelmsford Proposals also granted more autonomy to the provincial governments in India. The provincial governments were given the authority to make laws on a wide range of subjects, and the elected Indian ministers were given more control over the transferred subjects in their respective provinces. This was aimed at devolving more power to the provinces and increasing Indian participation in governance at the local level.

Overall, the Montague-Chelmsford Proposals were primarily focused on constitutional reforms aimed at granting more self-governance to Indians, with the introduction of diarchy, expansion of legislative councils, and increased provincial autonomy being the key features. While social, educational, and police reforms were important aspects of governance in British India, the Montague-Chelmsford Proposals specifically dealt with constitutional reforms, making Option 4: constitutional reforms the correct answer. These proposals were seen as an important step towards the eventual granting of independence to India, although they fell short of the complete self-governance demanded by Indian leaders at the time, leading to further demands for reforms in the subsequent years.