Martin Schongauer is known for his amazing ability to shade from the deep blacks to faint grays, using only lines, Option B is correct.
Martin Schongauer was an Alsatian engraver and painter. He was the most important printmaker north of the Alps before Albrecht Dürer, who collected his work.
His style shows no trace of Italian influence. However he had a very clear and organised Gothic, which draws from both German and Early Netherlandish painting.