Bismihi Ta'ala

This is the correct view. Why were you in doubt. This is also established from the Sunnah of Rasoolullah Sallallahu alaihi wasallam. In the Hadtih in which Aishah Radhiallahu Anha mentions that it was night time and she couldn't find the Prophet of Allah. She searched for him and found him him whilst he was in Sujood (prostration). In the Hadith she says, I grabbed his foot, which clearly indicates that the feet were seperated otherwise she wouldn't be able to hold both feet.

And Allah knows best.