The correct answer is A. SQL injection

The request contains a login attempt with the password value:

admin ' or '

This is characteristic of a SQL injection test because the tester is inserting SQL syntax into an input field to manipulate the backend database query. The single quote attempts to break out of the expected string value, and the OR condition attempts to alter the logic of the authentication query.

For example, a vulnerable login query might be manipulated so that the condition always evaluates as true, allowing authentication bypass.

B is incorrect because session hijacking involves stealing or reusing a valid session token or cookie. Although a cookie is present in the request, the attack shown is focused on the login input, not on taking over an existing session.

C is incorrect because brute forcing involves repeatedly trying many username or password combinations. The question shows a crafted payload, not repeated credential guessing.

D is incorrect because cross-site scripting involves injecting JavaScript or HTML into a web page so it executes in a user’s browser. The payload shown is SQL-like syntax, not client-side script code.

In PenTest+ terms, this falls under Attacks and Exploits, specifically web application attacks and authentication bypass attempts using SQL injection.