Explanation:

A subsidy is a sum of money granted by the government or other organizations to support a particular project or group. In this case, a manufacturing concern has received a subsidy of Rs. 40,000 from the government for working capital. Let's understand whether it is a capital receipt or a revenue receipt.

Capital Receipt:
- A capital receipt is a receipt that results in an increase in the capital of the business.
- Capital receipts are non-recurring in nature and do not affect the revenue of the business.
- Examples of capital receipts are the sale of fixed assets, capital contributions, loans, and grants for capital expenditure.

Revenue Receipt:
- A revenue receipt is a receipt that results in an increase in the revenue of the business.
- Revenue receipts are recurring in nature and affect the revenue of the business.
- Examples of revenue receipts are sales, interest received, rent received, and subsidies for working capital.

In this case, the manufacturing concern has received a subsidy for working capital, which is a revenue receipt. The reason for this is as follows:

- The subsidy is given to support the manufacturing concern's day-to-day operations, i.e., working capital.
- It does not result in an increase in the capital of the business.
- It affects the revenue of the business by increasing the funds available for day-to-day expenses, which in turn can increase the profit of the business.

Therefore, the correct answer is option 'B' - Revenue receipt.

Conclusion:
- It is important to understand the nature of receipts to properly classify them in the financial statements.
- While capital receipts and revenue receipts both increase the funds available to the business, they are treated differently in the financial statements.
- A subsidy received for working capital is a revenue receipt as it affects the revenue of the business.

Since received for working capital , the amount will be used for day to day expenses thus , revenue receipt