Which lines can be useful to show a thorny surface?

Correct answer: Sharp short lines

The direct answer is B: sharp short lines. Artists can suggest a thorny surface by repeating small pointed marks around or across the object. Step by step: identify the surface as prickly; choose angular, pointed marks; keep them short and clustered; place them where thorns or spikes would appear; the eye then reads the surface as rough and dangerous. A is wrong because round blurry lines suggest softness, smoothness or unclear edges, not sharp thorns. B is correct because pointed short strokes imitate the appearance of spikes. C is wrong because one horizontal strip cannot communicate repeated prickliness. D is wrong because empty space has no visible mark to show texture. Memory cue: sharp surface needs sharp marks.