Idealism, also known as immaterialism, asserts that:

Idealism, or immaterialism, is a philosophical stance asserting that reality is primarily mental or immaterial. This viewpoint proposes that the mind and its ideas constitute the foundation of existence, rather than physical matter. The core tenet of idealism is that everything that we perceive or understand is ultimately rooted in the mind.

Choosing the option that states "Only the mind exists" aligns with the idealist perspective, which posits that even though we experience a physical world, it is ultimately dependent on our mental constructs and perceptions. This means that reality cannot exist without being perceived by a conscious mind. Key philosophers associated with this view, such as George Berkeley, argued that objects only exist to the extent they are perceived or thought about.

In contrast, options that suggest physical matter or an equal regard for both mind and matter fundamentally contradict the principles of idealism. Idealism focuses on the primacy of the mental realm over physical reality, making the assertion that only the mind exists the most accurate reflection of idealist philosophy.