What vulnerability is detected in the web application here?

While testing web applications, you attempt to insert the following test script into the search area
on the company’s web site:
<script>alert(‘Testing Testing Testing’)</script>
Later, when you press the search button, a pop up box appears on your screen with the text
“Testing Testing Testing”. What vulnerability is detected in the web application here?

A.
Cross Site Scripting

B.
Password attacks

C.
A Buffer Overflow

D.
A hybrid attack