my $matches = 2;
my $threshold = 8;

my @results = ();

foreach my $row (@arr) {
  my $count;
  for (1..$#$row) {
    $count++ if($row->[$_] >= $threshold);
  }
  push @results, $row if($count >= $matches);
}

foreach(@results) {
  say join ",", @$_;
}

##</code><code>##

my $matches = 2;
my $threshold = 8;

my @results = grep {
  $matches <= scalar grep { $_ >= $threshold } @$_[1..$#$_];
} @arr;

foreach(@results) {
  say join ",", @$_;
}

##</code><code>##

D,6,7,8,8
F,4,8,8,8