Can I eliminate a choice/answer to a question in a drop list depending on how many times it has been chosen by other users? Like Google Choice Elimina

You are not able to use this functionality on simple dropdown list, however there are some widgets which is working with the same logic. I have explained this widgets as seen below.

1. Gift Registry

(Also check the another widget including quantity feature from here)

2. Appointment Slots widget

In addition, you can remove item by changing css when its limit are exceed. Inject following code your widget's custom css as you can see in the following screenshot below:

.list-item .line-through{

   display : none;

}

I hope it helps you. Please let us know if you have another questions.