Which option shows contrast in line weight?

Correct answer: One thick line and one thin line

Line weight is the apparent thickness or visual strength of a line. Contrast in line weight requires a difference in that same property, such as pairing a bold, thick line with a delicate, thin line. Option B does exactly this. Options A and C contain lines of equal thickness, while option D concerns equal dots rather than contrasting line weights, so none of them demonstrates the requested contrast.