If in a certain code, 'POT' is written as ATOP and 'TRAP' is written as APART, then how is 'ARENA' written in that code?

To solve this efficiently, I look at the first pair: 'POT' becomes 'ATOP'. \n\nI can immediately see a pattern: \n1. If I read 'POT' backwards, I get 'TOP'. (This is the **String Reversal** concept [29]).\n2. 'ATOP' is just 'TOP' with the letter 'A' added at the front. \n\nSo the hypothesis is: **Reverse the word + Add 'A' at the start.**\n\nNow, I verify this with the second pair: 'TRAP'.\n1. Reverse 'TRAP' to get 'PART'.\n2. Add 'A' at the front to get 'APART'. \nThis matches the question perfectly, confirming the rule [37].\n\nFinally, I apply this rule to the target word 'ARENA':\n1. Reverse 'ARENA' -> I get 'ANERA'.\n2. Add 'A' at the front -> I get 'AANERA'.\n\nLooking at the options, this matches (D). This method is much faster than assigning numbers to letters.