Identify each <a> tag separate

I am working on a project in ASP .Net MVC here i retrieve some data from database and show that by foreach loop. In loop along with data there is also a tag which actually a button. What I want is to identify which tag is clicked. For example this foreach loop generates 10 entries and same 10 tags for each entry and then user enters the tag of 4th entry what I want to identify that this data or tag is pressed.

Here is my code ..

@foreach (var opening in Model)
{
        <! -- Sponsors List -->
        <div class="showback">
            <h4><i class="fa fa-angle-right"></i> @opening.businessName</h4>
            <p>Offering: @opening.Opening.Description</p>
            <p>Budget Range: Rs.@opening.Opening.BudRangeLower - Rs.@opening.Opening.BudRangeUpper</p>
            <div class="btn-group">
                **<a  ID="btnModalPopup" class="btn btn-theme" >Approach</a>**
            </div>
        </div>

}