Matching objects in a drag and drop game C#

I am developing an educational game where I give the user a selection of words. The objective is to take these words and arrange them into a sentence by dragging each word individually and placing it into order on the provided area. I have an plane ready for each word to be dragged onto, but I am unsure how to determine whether the user has dragged their word into the correct position within the sentence.

I thought maybe I would be able to give an ID/Tag to each word, and a relating ID/Tag to each plane. When the two collide I could compare the two IDs and if they match, consider it a successful placement.

I’m wondering if anyone else has a better solution, as I am not sure about the best way to go about this?

Thanks in advance!

Your solution is great! Give each word an ID based on placement and each plane already has an id because their placement never changes.