What Latin verb meaning "to come" is the root of the word for "a thing that is kept as a reminder"?

The Latin verb meaning "to come" that serves as the root for the word for "a thing that is kept as a reminder" is indeed the correct choice. The verb "venio" translates to "I come" and is foundational to various related words in both Latin and its descendants, including English.

The term you are likely referencing, "memento," which means "a reminder" or "something that reminds," derives from the Latin verb "meminisse," meaning "to remember." While "memento" itself does not come directly from "venio," it is important to note that the concept of coming back to a memory aligns with the essence of "venio."

Various words associated with "venio" in English—such as "advent" or "venue"—demonstrate the ongoing influence of this verb, emphasizing its significance in the realm of relationships to arrival or presence. Thus, choosing "venio" accurately reflects the link between remembrance and the notion of coming back to a thought or memory.