Correct the sentence

 Hi, ravikumarkargam.

ravikumarkargam

Hi,

This is refering to a situation in the past.

Please let me know which of the following is correct? are all of them wrong?

I was just studying when she called? It's acceptable and moreover the most suitable here. She called before you were in the process of studying. Using "just" is more suitable with the Perfect Tenses.

I started studying when she called? The call happened when you studied.

I had just been started studying when she called? Wrong. "I had been studying for hours when she called." She called after you were studying or in the end of it.

If you want to emphasise moment when she called you and due to it you got interrupted, you can say: "I was studying when she called "

Thanks,

Raviff