c# - How to add custom attribute to Html.DropDownListFor option value instead of select value -

@html.dropdownlistfor(m => m.productid, new selectlist(model.products, "id", "productname", model.productid), htmlattributes: new { @class = "form-control", @id = "productsnew" }) 

the above code out below line of code

<select name="selectedcurrency" id="defaulttaxid" class="form-control">         <option value="aud">aud</option>        <option value="usd" selected="selected">usd</option>        <option value="npr">npr</option>        <option value="inr">inr</option>     </select> 

i need output this

<select title="select surfboard" class="selectpicker">   <option>select...</option>   <option data-thumbnail="images/icon-chrome.png">chrome</option>   <option data-thumbnail="images/icon-firefox.png">firefox</option>   <option data-thumbnail="images/icon-ie.png">ie</option>   <option data-thumbnail="images/icon-opera.png">opera</option>   <option data-thumbnail="images/icon-safari.png">safari</option> </select> 

how can achieve this. please can tell me