At least 3 viable fetuses:
The world was created, as the biblia sacra says, 10,000 years ago.
The biblia sacra is ... obviously ... a pack of lies.
This is the most intriguing of the possibilities ......
But who said they did nothing?
Realize that our scale and concept of time is completely meaningless to such a being.
The question is like a transient quark, flickering into and out of existence, and ...