extra option causing button to move up and down - html

Question

How do you position a button so it stays fixed?
I have an Angular app and when the 3rd option is displayed for a multiple choice, the next and back buttons move down.
Some of the questions only have 2 options and some have 3.
Is there a way to make it so that the buttons stay at one position? I tried using position property in css and margin-bottom, but no luck.
2 Options
3 Options
CSS
button {
background-color: #004273;
font-family: 'Roboto';
color: white;
border: 2px solid #93b9dd;
border-radius: 8px;
padding-top: 2%;
padding-bottom: 2%;
font-size: 1em;
}
.buttons2 {
width:48%;
float: right;
}
.buttons1 {
width: 48%;
float: left;
}
HTML
<h2 style="color: white;" align="center">{{statement}}</h2>
<h2 style="color: white;" align="center">{{question}}</h2>
<div class="radio-{{questionType}} col-sm-4 col-sm-offset-4 col-xs-offset-4">
<div class="form-check">
<mat-radio-group [(ngModel)]="selectedValue" class="options">
<mat-radio-button value="{{radio1}}">{{radio1}}</mat-radio-button> <br>
<mat-radio-button value="{{radio2}}">{{radio2}}</mat-radio-button> <br>
<span *ngIf="radio3">
<mat-radio-button value="{{radio3}}">
{{radio3}}
</mat-radio-button>
</span>
</mat-radio-group>
</div>
</div>
<div class="row">
<div class="col-sm-6 col-sm-offset-3" style="padding-top: 2%;">
<button *ngIf="state !== 1; else disabled_btn" class="buttons1 btn btn-primary" (click)="onClickedBack.emit(selectedValue)">BACK</button>
<ng-template #disabled_btn>
<button class="buttons1 btn" (click)="onClickedBack.emit(selectedValue)" disabled>BACK</button>
</ng-template>
<button class="buttons2 btn btn-primary" (click)="onClickedNext.emit(selectedValue)">NEXT</button>
</div>
</div>

Answer 1

You can use the :nth-child() CSS selector to modify the behavior of the options.
.options > :nth-child(3) {
height: 0;
overflow-y: visible;
}
The above selects the 3rd direct child of .options class element group, removes the height, but ensures that it still shows. You may have to adjust this based on other CSS.