"Are you asking?"
The way to create questions in Swedish is to put the verb before the subject. The only thing that can go before the verb in a question is a question word, like vem 'who', vad 'what' or similar.
If you get this as a multiple choice question, you have to click both Frågar du? and Frågar ni? if they're among the options.
du is said to one person and ni to more than one person. The English sentence is ambiguous.