kxip-app/src/app/quiz/mcq/mcq.component.html

<section class="question">
    <h3> {{ text }} </h3>
    
    <div class="options" [ngClass]="{'inactive' : selectedChoice }">
        <button *ngFor="let choice of choices"
        (click)="selectedChoice = choice.value"
        [ngClass]="{'correct': selectedChoice === choice.value && selectedChoice === correctAnswer, 'wrong': selectedChoice === choice.value && selectedChoice !== correctAnswer }">
            {{ choice.text }}

            <ion-checkbox mode="ios" [checked]="selectedChoice === choice.value"></ion-checkbox>
        </button>
    </div>
</section>