Which of the following bases is found in a window cleaner?

Ammonium hydroxide

The correct answer is option 2. Ammonium hydroxide.

Ammonium hydroxide \((NH_4OH)\) is a weak base that is effective in dissolving dirt, grease, and grime. This makes it a suitable cleaning agent for various surfaces, including glass.

It is also readily available and relatively inexpensive compared to other bases.

However, it's important to handle ammonium hydroxide with care as it can have a strong, unpleasant odor and irritate the skin and eyes.

While other bases like sodium hydroxide and calcium hydroxide are also effective cleaning agents, they are typically not used in window cleaners due to their stronger nature and potential for causing damage to surfaces or posing safety hazards.