code: protected function isSelected($arrOption)
  	{
  		if (empty($this->varValue) && empty($_POST) && $arrOption['default'])
  		{
  			return $this->optionSelected(1, 1);
  		}
  
  		if (empty($this->varValue) || !\is_array($this->varValue))
  		{
  			return '';
  		}
  
  		return $this->optionSelected($arrOption['value'], $this->varValue['unit']);
  	}
docs: Only check against the unit values (see #7246)
  
  @param array $arrOption The options array
  
  @return string The "selected" attribute or an empty string