1. Which of the following will cause a spark knock?

I couldn't find options for your question online, but I can give you an explanation so you can choose the correct option.

Explanation:

A spark knock is a form of unpredictable behavior that occurs in combustion, that is, in the chemical reaction that occurs between oxygen and an oxidizable material. Such combustion is usually manifested by incandescence or flame.

The spark knock is a detonation that occurs when there is a lot of pressure in the fuel.

Some situations in which this can happen are:

Engine overloaded. Maximum pressure in the cylinders. Engine overheated. Overheated air. Long and excessive engine ignition timing. Spark plug at high temperatures.