who is your parents? 这个在 中文 (简体) 里怎么说？

你的父母是谁 ？

你父母是谁？你爸爸妈妈是谁？

你的爸爸妈妈是谁? (The expected answers are the names of the parents or the student can point out parents in a group of people.)
If you want to ask about the names, you can ask directly 你的爸爸妈妈叫什么名字？

The question sounds a bit weird to me. I cannot imagine a situation to raise such a question. Maybe this is a question that your teacher asks so that the students can introduce/say a bit about their parents? In fact, I reckon, the best way to learn a foreign language is to put everything in a context. Maybe you can tell me more so that I can try and give you a Chinese equivalent.

你的父母是谁？

你的父母叫什么？ who are your parents？（answer： Mr. and Mrs. Li）
哪位是你的父母？who are your parents?( answer: standing there are my parents)
你的父母是谁？ who are your parents ? ( answer: standing there are my parents, their names are Mr. and Mrs. Li)

你父母是哪位？
你父母叫什么名字？

你的父母是谁？