I want to test the ability of students to read a passage and answer questions about it. Could you please come up with a good question for the passage "The Romans had a greater appreciation for the color green; it was the color of Venus, the goddess of gardens, vegetables and vineyards.The Romans made a fine green earth pigment, which was widely used in the wall paintings of Pompeii, Herculaneum, Lyon, Vaison-la-Romaine, and other Roman cities. They also used the pigment verdigris, made by soaking copper plates in fermenting wine. By the Second Century AD, the Romans were using green in paintings, mosaics and glass, and there were ten different words in Latin for varieties of green."? 

Which of the following is not a source of green pigment: earth, verdigris, or vegetables?