Why is first-party web tracking very difficult to prevent?

Why is first-party web tracking very difficult to prevent?
A . The available tools to block tracking would break most sites’ functionality.
B. Consumers enjoy the many benefits they receive from targeted advertising.
C. Regulatory frameworks are not concerned with web tracking.
D. Most browsers do not support automatic blocking.

Answer: D

Explanation:

Reference: https://www.opentracker.net/article/third-party-cookies-vs-first-party-cookies