Concept:
Modern India has attempted to revive the ancient Buddhist educational tradition through specialized institutions devoted to Pali, Buddhist philosophy, Buddhist history, and international Buddhist studies. Among these, Nava Nālanda Māhavihāra and the new Nālandā University are globally recognized.
Step 1: Understanding Nava Nālanda Māhavihāra.
Nava Nālanda Māhavihāra was established in 1951 in Bihar with the aim of reviving the ancient Nālandā tradition. It became an internationally respected institution for Buddhist studies, Pali language, and Buddhist philosophy.
Its major contributions include:
• Preservation of Pali literature
• Research in Buddhist philosophy
• International Buddhist exchange
• Publication of Buddhist texts
Thus, B is correct.
Step 2: Understanding modern Nālandā University.
The modern Nālandā University was re-established as an international university supported by several Asian countries. It officially began functioning in the 21st century and emphasizes:
• Buddhist studies
• Historical studies
• Ecology and environment
• International cultural dialogue
Thus, C is correct.
Step 3: Why the remaining options are incorrect.
• Mithilā University is a general university and not specifically a Buddhist centre.
• Nālandā Open University focuses on distance education generally.
• Rājasthān University is also a general state university.
Therefore, these do not qualify as major modern centres of Buddhist knowledge.
Step 4: Final conclusion.
Hence, the correct answer is:
\[
\boxed{(4)\ \text{B and C only}}
\]