I don’t really think so, as an oxymoron is two contradictory words put together. Eg The living death, a small crowd or bittersweet.
Plain and Surprise are not necessarily contradictory.
Context clue means other words in the story that helps the reader understand what the word means.
in this case, u need to find words in the story that helps the reader understand what the word "grabbed" means.
and I can't exactly give you the context clues because I don't have the story
Answer:
the letter will be wrote by them