Is there a way to reset the rest of the checkbox item, except one with the label "Nulo" with ion-checkbox?

Today in my code I am calling through WS a list of items that are in a topic of multiple checkboxes, and in this list I have a value called “Nulo”, with that I need when I select the value “Nulo”, the other items of the list are unchecked, minus the value “Nulo”. Because the value “Nulo” is within the same array, it is being unchecked along with the other options. Can someone help me?

My .html file is:

<ng-container *ngIf="pergunta.opcao_aberta == '0'" >
    <ion-item no-padding no-margin *ngIf="item.opcoes != 'Nulo'">
           <ion-label text-wrap>{{ item.opcoes }}</ion-label>
          <ion-checkbox formControlName="{{item.key}}" (click)="responder(pergunta, item)" (ionChange)="disabledCheckbox($event)"></ion-checkbox>
    </ion-item>
    <ion-item no-padding no-margin *ngIf="item.opcoes == 'Nulo'">
        <ion-label text-wrap>{{ item.opcoes }}</ion-label>
        <ion-checkbox type="checkbox" formControlName="{{item.key}}" [checked]="uncheck" (click)="responder(pergunta, item)" (ionChange)="disabledWithNull($event)"></ion-checkbox>
    </ion-item>
</ng-container>

My .ts file:

    getCheckTotal = 0;
    disabledDone: boolean = false;
    limiteRespostas = 2;
    checked : boolean = false;
    uncheck = false;

public disabledCheckbox(e:any) {
        if (e.checked != this.checked) {
            if (e.checked) {
                this.getCheckTotal++;
                console.log(this.getCheckTotal);
                this.uncheck = false;
                if (this.getCheckTotal > this.limiteRespostas) {
                    this.showAlert('Atenção!', `Você só pode escolher ${this.limiteRespostas} opções!`);
                    e.checked = false;
                    return;
                }
                this.disabledDone = true;
            } else {
                this.disabledDone = false;
            }  
        } else {
            this.getCheckTotal--;
            console.log(this.getCheckTotal);
        }
    }

public disabledWithNull($event) {
        this.disabledDone = true;
        if($event.checked){
        this.disabledDone = false;
        } else {
        this.disabledDone = true;
        }
        this.form.reset();
    }