How do I replace all instances of a class in JS with code injection?

Question

Let's say I want to replace all instances of options on a form (Agree/Disagree/Neutral). I can't seem to make this happen for any more than the first instance of each, rather than down the entire page.

Example

Here is where I'm at so far:

<script>
function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      if (oldonload) {
        oldonload();
      }
      func();
    }
  }
} 
addLoadEvent(function() {

//Songwriting
  sqsRadio = document.getElementsByClassName("option")[0].innerHTML;
  myRadio = sqsRadio.replace("Strongly Disagree", "Fortement Désaccord");
  document.getElementsByClassName("option")[0].innerHTML = myRadio;

  sqsRadio = document.getElementsByClassName("option")[1].innerHTML;
  myRadio = sqsRadio.replace("Disagree", "Désaccord");
  document.getElementsByClassName("option")[1].innerHTML = myRadio;

  sqsRadio = document.getElementsByClassName("option")[2].innerHTML;
  myRadio = sqsRadio.replace("Neutral", "Neutre");
  document.getElementsByClassName("option")[2].innerHTML = myRadio;

  sqsRadio = document.getElementsByClassName("option")[3].innerHTML;
  myRadio = sqsRadio.replace("Agree", "d'Accord");
  document.getElementsByClassName("option")[3].innerHTML = myRadio;

  sqsRadio = document.getElementsByClassName("option")[4].innerHTML;
  myRadio = sqsRadio.replace("Strongly Agree", "Fortement d'Accord");
  document.getElementsByClassName("option")[4].innerHTML = myRadio;

});
</script>