Shang dynasty bronze pieces are rare and therefore more valuable than those from other time periods.

the source of some of the raw materials used to make bronze was exploited only until the end of the Shang dynasty.

bronze was used for a short time during the Shang dynasty before different metals were used to make artifacts.

methods used to analyze bronze artifacts are not useful on pieces that are dated after the Shang dynasty.

English

PASSAGE: Archaeologists have been debating the origin of a rare form of lead found in Shang dynasty (1766–1046 BCE) bronze artifacts since its presence was discovered in China in the 1990s. Different researchers have proposed theories on which regions of the world would have had the raw materials containing the specific lead in these artifacts, but no conclusive evidence has been presented. What is intriguing is that bronze artifacts from China dated after the Shang dynasty do not contain this form of lead, suggesting that _____

 QUESTION: Which choice most logically completes the text?

