The correct answer is option B - to ascertain the cost of the manufactured goods.

Explanation:
A manufacturing account is a type of financial statement that is prepared by manufacturing companies to determine the cost of producing goods. It is an important part of the overall accounting process for manufacturing companies as it helps in analyzing the costs involved in the production process.

Here is a detailed explanation of the purpose of a manufacturing account:

1. Ascertain the cost of the manufactured goods:
The primary purpose of preparing a manufacturing account is to determine the cost of the goods that have been manufactured during a specific period. It includes all the direct costs and indirect costs associated with the production process. Direct costs include raw materials, direct labor, and direct expenses, while indirect costs include manufacturing overheads such as factory rent, depreciation of machinery, utilities, etc. By calculating the total cost of production, the manufacturing account helps in evaluating the efficiency and profitability of the manufacturing process.

2. Determine the value of the closing stock:
The manufacturing account also helps in determining the value of the closing stock of finished goods. This is important for inventory valuation and financial reporting purposes. The closing stock is included in the manufacturing account as a credit entry, representing the value of the finished goods that are still in the inventory at the end of the accounting period.

3. Calculate the cost of goods sold:
By deducting the value of the closing stock from the total cost of goods manufactured, the manufacturing account helps in calculating the cost of goods sold during the period. This information is crucial for determining the gross profit or loss on the sale of goods.

4. Provide cost information for decision-making:
The manufacturing account provides detailed cost information that can be used by management for decision-making purposes. It helps in identifying cost variances, analyzing cost trends, and making informed decisions regarding pricing, production volume, cost control, and other aspects of the manufacturing process. This information is valuable for improving operational efficiency and profitability.

In conclusion, the manufacturing account is prepared to ascertain the cost of the manufactured goods. It helps in determining the total cost of production, calculating the value of closing stock, calculating the cost of goods sold, and providing cost information for decision-making purposes.

D