use strict;
use warnings;

my %hash;

while (<DATA>) {
	chomp;
	$hash{Makes}{$_} = undef;
}

print 'Before:', "\n";
print "$_\n" for keys %{ $hash{Makes} };

my $item = getCategoryItem( 'Makes', \%hash );
print "\n", 'Selected:', "\n", $item, "\n\n";

print 'After:', "\n";
print "$_\n" for keys %{ $hash{Makes} };

sub getCategoryItem {
	my ( $category, $hashRef ) = @_;
	my @items = keys %{ $hashRef->{$category} } or return undef;
	# undef is returned if no items

	my $item = $items[ rand $#items + 1 ];
	delete $hashRef->{$category}{$item};
	return $item;
}

__DATA__
Ford
Chevrolet
KIA