I have the following code in my Lightning Component

    <aura:iteration items="{!v.wrapAccountList}" var="arItem" indexVar="index">
    <tr>
        <div class="slds-truncate">
          <lightning:select name="rejectReasonPick" label="" value="{!arItem.acc.rejectReason}">
                                    <aura:iteration items="{!v.rejectReasonPickList}" var="reason">
                                        <aura:if isTrue="{!arItem.acc.rejectReason  == reason.value}">
                                            <option text="{!reason.label}" value="{!reason.value}" selected="true"/>
                                            <aura:set attribute="else">
                                                <option text="{!reason.label}" value="{!reason.value}"/>
                                            </aura:set>
                                        </aura:if>
                                    </aura:iteration>
                                </lightning:select>
                                </div>
        <td>
        <div class="slds-button-group" role="group">
                                    <lightning:buttonIcon aura:id="addButton" iconName="utility:close" alternativeText="Reject" variant="border-filled" onclick="{!c.handleAddTaskAction}" name="{!index}"/>
        </div>
        </td>
    </tr>

What I Would like to do is that when the Reject button above is clicked, `rejectReasonPick` field above should become mandatory (red highlighted). Once that value is populated, and reject is clicked record will be saved.

Here, `wrapAccountList` is a wrapper. Multiple records are present in the wrapper as a list. When reject corresponding to one record is clicked, the field corresponding to that record , only would be highlighted. I am really stuck in this one and any code snippet or solution would be really helpful