Explanation:

- The Matching concept involves aligning expenses with revenues in the period they are incurred or earned.

- The Money Measurement concept states that only events measurable in monetary terms are recorded. If factors like a new competitor or an internal department rift cannot be quantified in money, they're not recorded.

- The Revenue Recognition principle dictates when revenue is considered earned, focusing on realizing revenue when it is earned, regardless of when the cash is received.

- The Cost principle states that assets are recorded based on their original purchase costs.

Option: 2, Money Measurement - This principle focuses on recording only quantifiable financial data. Therefore, qualitative events aren't recorded in books.