What do you think would be the Answer?

WHAT HACKING TECHNIQUE WAS USED?

I recently built a beautiful website with a sleek user interface and hosted it online. However, to my surprise, when I returned the next day, I discovered that my site had been hacked! The user interface was completely scattered, and nothing looked right.

So, what kind of attack could have caused this mess?

Was it:

a) Spamming
b) Phishing
c) SQL Injection
d) Cross-Site Scripting (XSS)
e) Database Spoofing

Let me know what you think in the comments below! 💬