The correct answer is: (A) and (R) both are correct but (R) is not a correct explanation of (A).
Assertion (A) is correct. Most of the development banks in India have setup private commercial banks after the introduction of capital adequacy norms. This is because the capital adequacy norms made it difficult for development banks to raise capital, and setting up private commercial banks was a way for them to raise capital and continue to operate.
Reason (R) is also correct. Development banks in India have not adhered to their basic objectives. This is because they have been more focused on raising capital and making profits than on providing development finance.
However, reason (R) is not a correct explanation of assertion (A). The fact that development banks in India have not adhered to their basic objectives does not explain why they have set up private commercial banks. There are other reasons why they may have done this, such as the need to raise capital or the desire to expand into new areas of business.
In conclusion, both assertion (A) and reason (R) are correct, but reason (R) is not a correct explanation of assertion (A).