Dropdown exceeds field size [duplicate]

function shortString(selector) {
  const elements = document.querySelectorAll(selector);
  const tail = '...';
  if (elements && elements.length) {
    for (const element of elements) {
      let text = element.innerText;
      if (element.hasAttribute('data-limit')) {
        if (text.length > element.dataset.limit) {
          element.innerText = `${text.substring(0, element.dataset.limit - tail.length).trim()}${tail}`;
        }
      } else {
        throw Error('Cannot find attribute \'data-limit\'');
      }
    }
  }
}

window.onload = function() {
  shortString('.short');
};

select {
  width: 250px;
}

option {
  width: 250px;
}

<select name="select" id="select">
  <option class='short' data-limit='37' value="Select your University">Select your University</option>
  <option class='short' data-limit='37' value="Bangladesh University of Engineering and Technology">Bangladesh University of Engineering and Technology</option>
  <option class='short' data-limit='37' value="Mawlana Bhashani Science and Technology University">Mawlana Bhashani Science and Technology University</option>
</select>

var e=document.querySelectorAll('option')
e.forEach(x=>{
if(x.textContent.length>20)
x.textContent=x.textContent.substring(0,20)+'...';
})

select
{
width:160px;
}

<select>
<option>fwefwefwefwe</option>
<option>fwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwefwe</option>
</select>