用于根据其他两个单元格的值添加文本的公式

I have a large spreadsheet that needs a bit of fine-tuning. Column A contains numbers from 1-4000, sequentially-listed. Column B contains some of those same numbers, but many numbers are skipped (for example: 1, 5, 6, 7, 11, 12, 25...); those numbers are not "spaced out" relative to the numbers in column A. Column C contains text entries related to the Column B values. I need to add a formula in column D that will evaluate whether the number in A1 (for example) matches the number in B1, and if it does match it should place the value of C1 in D1. Likewise, if A2 matches B2, then the value of C2 should be placed in D1.I have a large spreadsheet that needs a bit of