TPO4-CAVE ART IN ENROPE - 英檢

希望有人可以幫忙解答一下
不是很懂這個邏輯

Another explanation for the focus on animals might be that t
hese people sought to improve their luck at hunting. This theory is
suggested by evidence of chips in the painted figures, perhaps made
by spears thrown at the drawings. But if improving their hunting
luck was the chief motivation for the paintings, it is difficult to explain
why only a few show signs of having been speared. Perhaps the paintings
were inspired by the need to increase the supply of animals.

7．According to paragraph 3, scholars explained chips in the
painted figures of animals by proposing that
○Upper Paleolithic artists used marks to record the animals they had seen
○the paintings were inspired by the need to increase the supply of animals
for hunting
○the artists had removed rough spots on the cave walls
○Upper Paleolithic people used the paintings to increase their
luck at hunting

答案是D 不過為什麼不是B呢?

因為文章說D選項 it is difficult to explain
why only a few show signs of having been speared
還是說 因為是指 scholars...proposing that(所以不用管其它解釋?)

煩請有經驗的解答一下
感謝!!

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