Creating a new All-India service is a significant decision that requires a proper constitutional framework. Among the given options, the correct answer is option 'C', which suggests that a resolution under Article 312 of the Constitution can be used to create a new All-India service. Let's explore this answer in detail:

Article 312 of the Indian Constitution:
Article 312 of the Indian Constitution empowers the Rajya Sabha to pass a resolution by a majority of not less than two-thirds of the members present and voting, declaring that it is necessary or expedient in the national interest to create one or more All-India services. This article provides a constitutional provision for the creation of new All-India services, which are crucial for the efficient functioning of the government and administration.

Process of creating a new All-India service under Article 312:
To create a new All-India service under Article 312, the following process needs to be followed:

1. Proposal: The proposal to create a new All-India service must be initiated by the central government, keeping in mind the national interest and the need for such a service.

2. Rajya Sabha Resolution: The central government presents a resolution in the Rajya Sabha, which is the upper house of the Parliament. This resolution must be passed by a majority of not less than two-thirds of the members present and voting.

3. Lok Sabha Approval: After the resolution is passed by the Rajya Sabha, it is then presented in the Lok Sabha, which is the lower house of the Parliament. The resolution must be approved by a simple majority in the Lok Sabha.

4. President's Assent: Once the resolution is passed by both houses of Parliament, it is sent to the President of India for his assent. The President's assent is necessary for the resolution to become effective.

5. Creation of the All-India Service: After receiving the President's assent, the central government can proceed with the creation of the new All-India service. The government will establish the rules and regulations governing the service, including recruitment, training, and service conditions.

Importance of Article 312:
Article 312 provides a constitutional mechanism for the creation of All-India services, which are essential for maintaining uniformity and efficiency in the administration of the country. These services play a crucial role in implementing various policies and programs of the central government across different states and union territories. By creating new All-India services, the government can ensure effective governance and better coordination between the center and the states.

In conclusion, creating a new All-India service requires following a constitutional process, and the correct method is through a resolution under Article 312 of the Constitution. This article empowers the Rajya Sabha to pass a resolution by a two-thirds majority, declaring the need for a new All-India service. Once the resolution is passed by both houses of Parliament and receives the President's assent, the government can proceed with the establishment of the new service.