JSFiddle - React, Tailwind, and code Playground

HTML

<select>
	<option value="-1">---</option>
    <option value="alimentation">Choix 1</option>
    <option value="2">Choix 2</option>
    <option value="3">Choix 3</option>
    <option value="4">Choix 4</option>
    <option value="5">Choix 5</option>
    <option value="6">Choix 6</option>
    <option value="7">Choix 7</option>
    <option value="8">Choix 8</option>
</select>
<div id="alimentation">Alimentation</div>
<div id="2">2</div>
<div id="3">3</div>
<div id="4">4</div>
<div id="5">5</div>
<div id="6">6</div>
<div id="7">7</div>
<div id="8">8</div>

JavaScript

function selectionDone(e){
	
	var showAll = (e.target.value == "-1") ? 1 : 0,
		i = 1,
		l = select.children.length;

	for (; i<l; i++) {

		document.getElementById(select.children[i].value).style.display = (showAll) ? "block" : "none";

	}

	!showAll && (document.getElementById(e.target.value).style.display = "block");
	
}

var select = document.querySelector("select");

select.children[0].setAttribute("selected", "");

select.addEventListener("change", selectionDone, false);