Post-Impressionism

Post-Impressionism is a loose umbrella for painters working just after Impressionism (roughly the 1880s-1900s) who kept its bright colour and everyday subject matter but pushed further in different individual directions: Cézanne toward underlying geometric structure, Van Gogh toward expressive, emotional colour and thick, energetic brushwork, Seurat toward the systematic dot-based technique of Pointillism.

Because the artists grouped under this name went in genuinely different directions, an exam answer is stronger naming one specific painter's specific innovation than describing 'Post-Impressionism' as a single unified style - pick one artist and know their distinguishing feature solidly.