nRF Connect SDK Fundamentals : Lesson 5 Quizz : RTS question

[MDev]

I have problem with one question of the lesson 5 Quizz of the "nRF Connect SDK Fundamentals" course (Dev Academy)

https://academy.nordicsemi.com/courses/nrf-connect-sdk-fundamentals/lessons/lesson-4-serial-communication-uart/quizzes/lesson-5-quiz/

Here is the question :

Regarding the name, RTS is "request to send", so RTS indicate that the device is ready to receive and not to send, so the answer 2 seems not the good one.

RTS is used to indicate that the device is busy or not, and ready or not to accept new data. So answer 4 seems to be the closest one to what can be a good answer.

What do you think ?