Color, motion, orientation, and size are the strongest search guides

Correct: B — Color, motion, orientation, and size

Wolfe & Horowitz (2017) sorted the literature on guiding features into tiers of evidence. They classified four attributes — color, motion, orientation, and size — as 'undoubted' guides of attention because target–distractor differences on these dimensions reliably produce efficient (near-flat-slope) search across many studies. A second tier of 'probable' guides included luminance contrast, depth, and shape. They argued that semantic factors and scene context can bias search but typically operate atop these basic visual features rather than substituting for them. The taxonomy is now the standard reference for which low-level features genuinely steer the moving eye during visual search.