Below are descriptions of internal control problems. Identify the one best internal control principle that is related to the problem described. 1. The same person opens incoming mail and posts the accounts receivable subsidiary ledger. select principle of internal control 2. Three people handle cash sales from the same cash register drawer. select principle of internal control 3. A clothing store is experiencing a high level of inventory shortages because people try on clothing and walk out of the store without paying for the merchandise. select principle of internal control 4. The person who is authorized to sign checks approves purchase orders for payment. select principle of internal control 5. Some cash payments are not recorded because checks are not pre-numbered. select principle of internal control 6. Cash shortages are not discovered because there are no daily cash counts by supervisors. select principle of internal control 7. The treasurer of the company has not taken a vacation for over 20 years. select principle of internal control