IMHO logically you need:
$Count = 1
Reason is that if multiple lines are selected, you need to inform the user that only one should be selected.
But $Count>=1 works too, it will only not generate an error and select the first in the list.
I Suppose it wil b:e
$Count > = 1
As I suppose that if there is more than one it takes the first one (with the head activity) and pass it (with the sow page) to the next page...
It would be
$Count >= 1
since you want to check if the list has one or more elements in it. Later via 'Head’ operation, you take the first one.