Which of the following is a notable characteristic of Impressionism?

Impressionism is characterized by its emphasis on capturing the effects of light and movement in a spontaneous and immediate way. Artists of this movement sought to portray a moment in time, often using quick, loose brushwork and vibrant colors to convey the fleeting qualities of light as it interacts with the environment. This focus on how light can alter the perception of a scene is fundamental to Impressionist works, setting them apart from earlier styles that favored more rigid structures and subject matter.

While other options present characteristics that may describe different art movements, they do not align with the core principles of Impressionism. Significant detail in outlines, a predominance of dark colors, or a reliance on geometric shapes do not effectively represent the fluid and dynamic nature that Impressionists aimed to capture in their art.