In addition to being China’s first administrators, in the sense that they developed a coherent bureaucracy for their empire, (the first literate culture in East Asia were the Shang, and they were well known for crafting) ornate bronze ritual vessels.

A. the first literate culture in East Asia were the Shang, and they were well known for crafting
B. the first literate culture in East Asia were the Shang, well known as the crafters of
C. the Shang, as the first literate culture in East Asia, is well known for its crafting
D. the Shang were the first literate culture in East Asia and are well known as the crafters of
E. the Shang were the first literate culture in East Asia and well known for its crafted


I chose B because in D "are well known" isn't correct tense, it should be past tense. So I chose B why the OA is D??? Pls explain me