The correct answer is (d) partly rigid and partly flexible.
A rigid constitution is one that is difficult to amend. A flexible constitution is one that is easy to amend. The Indian Constitution is partly rigid and partly flexible. Some parts of the Indian Constitution, such as the basic structure, are difficult to amend, while other parts are easier to amend.
The basic structure of the Indian Constitution is the fundamental principles on which the Constitution is based. These principles include the sovereignty of India, the unity and integrity of India, the secular nature of the state, and the democratic nature of the state. The basic structure cannot be amended by Parliament.
Other parts of the Indian Constitution are easier to amend. For example, the procedure for amending the Constitution can be amended by Parliament. The powers of the President and the Prime Minister can also be amended by Parliament.
The Indian Constitution is a hybrid constitution, which means that it is a combination of a rigid and a flexible constitution. This allows the Indian Constitution to be both stable and adaptable to changing circumstances.