@if ($availableRacks->count() == 0)
    <option value="" selected disabled>
        *No puede asignarse con mas racks*
    </option>
@else
    <option value="" disabled selected>*Selecciona una*</option>
    @foreach ($availableRacks as $rack)
        <option value="{{ $rack->id }}" @selected(old('rack') == $rack->id)>
            {{ $rack->location }}
        </option>
    @endforeach
@endif