The author\u2019s purpose for writing this passage is to _________ .

The author\u2019s purpose for writing this passage is to inform the reader about tumors. You can identify that the author is informing you about tumors because he or she tells you what causes them, how they form, and which ones are cancerous. The author is not instructing the reader on how to do something, persuading the reader to do something, or endorsing a product for the reader to purchase; therefore, the other options can all be eliminated.