Somebody could me explain in this quizz DOM & Events

Question

Somebody could me explain in this quizz DOM & Events
Module 7 Quiz https://www.sololearn.com/Play/JavaScript
I dont understand why the first answer its(" p")

var arr = document

getElementsByTagName("p");
for(var x=0; x<arr.length; x++)
{
arr[x].innerHTML="SoloLearn";
}

Answer 1

the answer:
this quiz want you to write sololearn in <p> tag. 'cause <p> tag usually used for text.

var arr = document.getElementsByTagName("p");
/* this code is call <p> tag from HTML document */

for(var x=0; x<arr.length; x++)
{
arr[x].innerHTML="SoloLearn";
}