a:
        (our $VERSION = '3.0')
$VERSION = 3.0

b:
my $VERSION = 2.0;
$VERSION = 

c:
Undefined subroutine &main::qv called at (eval 3) line 1, <> line 2.
our $VERSION = qv(1.0);
$VERSION = 

d:
use version; our $VERSION = qv(1.0);
$VERSION = v1.0.0