Why does my Audi A4's engine sometimes make knocking noises?

I have noticed that my Audi A4's engine occasionally makes a knocking noise, especially when accelerating. Is this something I should be concerned about?

Most likely, this knocking noise is due to pre-ignition, or detonation, which occurs when the air and fuel mixture in the engine combusts at the wrong time. This can be caused by several factors, including low-quality fuel or a malfunctioning knock sensor. It is important to have this issue inspected and resolved by a professional mechanic to avoid any potential engine damage.