### Clue: 65, or 54? (OAP's essential verbal test) (4)
### Answer: VIVA 
 ### Explanation: Definition: verbal test
VIV, which can be split as VI V = 6 5, or V IV = 5 4, + [O]A[P]. To be picky, a Viva is an *oral* (spoken) test, not verbal (using words).