Final answer:
The correct answer is 'd. smudged line that blends into the background,' as it is not representative of the techniques used by Post-Impressionists or Impressionists, known for vivid colors, expressive lines, and bold brushstrokes.
Step-by-step explanation:
The stylistic characteristic that led to the selection of the artist which does not align with Post-Impressionist or Impressionist techniques is 'd. smudged line that blends into the background.' Post-Impressionists were known for their use of vivid colors, expressive lines, and bold brushstrokes. Their techniques often involved broad strokes that could articulate the emotion and feel of the image, creating expressive images that, while sometimes appearing distorted, conveyed an expressive truth. The Impressionists and Post-Impressionists typically used visible, discrete brushstrokes, rather than smudging lines to blend colors into the background.
Contrasting with these styles, color field artists focused on the consistency of their colors, seeking to eliminate any trace of brushstrokes for a smooth, textureless appearance, which sometimes required paint to be applied in such a way that it would blend into the canvas. But this practice is not commonly associated with either Impressionist or Post-Impressionist techniques, who instead, relied on the juxtaposition of strokes or patches of color to create an image.