foreach my $sql ( 
    $sql_count_A_Ref_vs_Comp, 
    $sql_count_A_Ref_vs_Comp_B, 
    $sql_count_A_ref_vs_Comp_C, 
    $sql_count_A_Ref_vs_Comp_D 
) {
    my $sth = $dbh_B->prepare( $sql ) or die "Cannot prepare: " . $dbh_B->errstr();
    $sth->execute() or die $sth->errstr;
}