Archaeologists have discovered various paintings on the walls and ceil

Archaeologists have discovered various paintings on the walls and ceiling of a Chinese cave whose entrance was blocked by a volcanic eruption in the 25th century B.C. and only recently cleared by an earthquake. Since the paintings depict warriors using Type C bronze weapons, these archaeologists have concluded that Type C bronze weapons were already widely used in this area by 2500 B.C., far earlier than was previously believed.

Which of the following pieces of additional evidence would most seriously weaken the archaeologists’ conclusion?

(A) Another entrance to the cave remained clear until a second volcanic eruption 1,000 years after the first.

(B) Archaeologists have evidence that Type C bronze weapons were in wide use in areas of present-day India as early as 2500 B.C.

(C) Alternative methods of dating place the time of the volcanic eruption somewhat earlier, at around 3000 B.C.

(D) Most experts believe that Type C bronze weapons were not in use anywhere in present-day China until 2000 B.C.

(E) The paintings were very faded when the archaeologists found them, making identification of the depicted weapons difficult.