Radio Button Tag Helper sets every radio button to checked

Both of these radio buttons will have checked="checked" on them.  Why would the tag helper add that.  How do you specify that none of them should be checked?

<div class="form-group">
<label>
<input name="Answer" type="radio" asp-for="Answer1" value="@Model.Answer1" /> @Model.Answer1
</label>
</div>

<div class="form-group">
<label>
<input name="Answer" type="radio" asp-for="Answer2" value="@Model.Answer2" /> @Model.Answer2
</label>
</div>