The startup balances of a trial balance are extracted from the A balance sheet. B ledger. C journal. D source document.

Step 1: Answer Question 42. The startup balances of a trial balance are extracted from the ledger, which contains all the accounts with their debit and credit balances. B) ledger. Step 2: Answer Question 43. When stock is updated after every purchase and sale transaction, the system of recording is known as Perpetual Inventory. This system continuously tracks inventory balances. D) Perpetual Inventory. Step 3: Answer Question 44. A document established by a person known as a subscriber, typically promising to pay a sum of money, is a promissory note. C) promissory note. Step 4: Answer Question 45. The main activity of a commercial enterprise is generally focused on buying and selling of goods, often without transforming them significantly, or producing goods and selling them to customers. Option C is the most general and accurate description of a commercial enterprise's core activity. C) buying and selling of goods without transformation. Step 5: Answer Question 46. An allowance paid to a worker as a result of his or her sale of goods or services is known as commission. This is typically a percentage of sales. B) commission. Step 6: Answer Question 47. Consigned packagings and the value added tax (VAT) are typically added to the base price of goods or services on an invoice. B) additions on an invoice. Step 7: Answer Question 48. In accounting, the left side of an account is conventionally called the debit side. B) debit balance. Step 8: Answer Question 49. The permanent inventory system is also called Perpetual inventory. This is a system where inventory records are continuously updated. B) Perpetual inventory. Step 9: Answer Question 50. The principle which states that for every transaction, there must be at least one debit and a corresponding credit entry is called the Double entry principle. This ensures that the accounting equation remains balanced. D) Double entry principle. What's next?