here is my code

```
<select class="form-control input-transparent" id="select-field" name="address" ngModel required>
     <optgroup *ngFor="let wallet of wallets" label="{{wallet.label}}">
         <option value="{{ wallet.address }}" [selected]="wallet.address == wallets[0].address">{{ wallet.address }}</option>
     </optgroup>
</select>

```

I want to select first option as selected but still on default value was selected