The liability which should be paid within a period of one year is known as a/an:

In accounting, liabilities are obligations that a company owes to outside parties. These are classified based on their due date, which is crucial for assessing a company's liquidity and financial health.

• A Current liability is an obligation that is expected to be settled within one year or within the company's normal operating cycle, whichever is longer. These liabilities are typically paid using current assets. Common examples include accounts payable (money owed to suppliers), short-term loans, accrued expenses (like salaries or utilities owed), and the current portion of long-term debt.
• Current asset (A) is incorrect because it refers to assets expected to be converted into cash or used up within one year, such as cash, inventory, and accounts receivable.
• Fixed asset (C) is incorrect because it refers to long-term tangible assets used in the business operations, like property, plant, and equipment, which are not expected to be converted into cash within a year.
• Long-term liability (D) is incorrect because these are obligations that are not due for more than one year, such as bonds payable or long-term notes payable.

Therefore, the one-year timeframe is the key determinant for classifying a liability as current, making option B the correct answer.