In order to understand it fully you will need basics of laravel (MVC),
Let suppose, you have controller. In my case I made a separate table for drop down values.
My Approach --- Separate table for values of drop down, you can try different approach but my explanation was mainly focused on concept.

Note: PersonInfo is model, sampleType is model of my drop down values and don't forget to make a route for the controller.
ExampleController{
public funtion getValues($id){
/*
I am fetching information of a single row from the database by id and
then passing it to the view. The $id to the function came from the
request by your view/form.
I also fetched the values of drop down from the separate table
of database and passed it to the exampleView.
*/
$selectedValue=PersonInfo::findOrFail($id);
$sampleType=SampletypePicker::all(); //model for fetching all values of drop down
return view('exampleView',compact('selectedValue','sampleType));
}
}
So, in the above controller I fetched all values and passed it to the ExampleView. Now in your View file you have to work likewise.
exampleView.blade.php add the below code
<?php $options=$selectedValue->sample_type ?> //note take the value from the database which stored for the individual record and match it with the selected one.
<select class="form-control" name="test">
<option>Select Test Type</option>
@foreach ($sampleType as $value)
<option value="{{ $value->sample_type }}" {{ ( $value->sample_type == $options) ? 'selected' : '' }}>
{{ $value->sample_type }}
</option>
@endforeach
</select>
It is one of the best approach when you want to add dynamic values to the drop down. I mean if you want to add more values to the select tag options then this is the best approach.
Another Approach - take the idea
<?php $months = array("Jan", "Feb", "Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"); ?>
<?php $options=$patient_data->month ?>
@if($patient_data->month)
<select id="expiry_month" name="month" class="form-control-sm">
@foreach($months as $month)
<option value="{{$month}}" {{($month==$options)? 'selected':'' }}>{{$month}}</option>
@endforeach
</select>
@endif
<span class="select-icon"><i class="zmdi zmdi-chevron-down"></i></span>
</div>
OUTPUT of ABOVE CODE

<option value="5 Feet" @if($profile_data['Height'] == '5 Feet') selected @endif >5 Feet </option>And repeat for the other options.