[Grammar] My telephone rang when we were having breakfast.

[Soseki]

Hello,

A. My telephone rang when we were having breakfast.
https://www.englishclub.com/esl-games/grammar/jumbled-tenses-mixed-past-6.htm
The sentence is the wrong answer.

The anwer is:
B. We were having breakfast when my telephone rang.

Why is A. wrong?

Thank you

 

[Tdol]

I think it's OK. It's probably an issue with the limitations of a drag and drop exercise that doesn't allow for multiple possibilities.