.option100{
width:100px !important;
}
<select id="fieldOfInterestSelect" name="fieldOfInterest" class="form-control" required="">
<option value="-1">SELECT ONE</option>
<option value="4893" class="option100">Actual(R)rrrrrrrrrrrrrrrr</option>
<option value="4891" class="option100">Customerrrrrrrrrrrrrr</option>
<option value="4892" class="option100">Daterrrrrrr</option>
<option value="4894" class="option100">Forecast(R)RRRRRR</option>
</select>
In cases where the text within the options is longer than the allotted space, it should wrap automatically to fit within the container's width.