A fixed prosthesis appears whiter than the adjacent tooth. The same appearance happens with under-reduction and insufficient depth. What was the issue?

When a crown appears WHITER/BRIGHTER than adjacent teeth, and this happens with insufficient tooth preparation depth, the issue is VALUE. VALUE = lightness/brightness. When there's not enough space for the ceramic, the technician must use MORE OPAQUE porcelain (to mask the metal substrate or to achieve color), which increases the VALUE (brightness) of the crown. High value = whiter/brighter appearance. The crown looks 'bleached' or too light. Under-reduction → insufficient ceramic thickness → high value crown. B is correct.