Course question - please explain answer...thanks in advance

Choose the odd one that doesn’t fit into the group. nǎr jǐ ma le - ( correct ) Can someone please explain why le is correct? I must be missing something simple? Just an idea - but perhaps a breif explanation of why the answer is correct for each question in the course would be very helpful, or to go further, maybe users could submit an answer and have people vote on the best one? just ideas....thanks for the course!!

I think it's because the first three are used to ask something. Nar - Where Ji - Is used when asking for an amount like what time or how many people. (I think) Ma - Used at the end of questions Le is used at the end when speaking about something that has already happened. At least I believe that's why. I could be wrong. Lol.

大家好！ You are 100% correct Dionna! As you said, the first three are interrogative pronouns and are used when we ask questions whereas 了is a particle that expresses the completion of an action. That is a very good suggestion Daniel, I shall pass that on to our team and see what can be done! 加油加油！Keep up the good work! - Lin Ping

WHOOT! Wow, you don't know how happy your message made me Lin!! I'm feeling really good right now since I was actually correct. I'm going to go and reward myself with more studying today!!! Hahaha.