Answer:
D. His aunts and grandmothers taught him to count while they sorted out the materials used to make the abstract designs in the native baskets.
Step-by-step explanation:
Letter A talks nothing about being smart or not, only about a cultural aspect of his. Letter B is also a cultural problem. C is just an introduction of the character. On letter D, though, it is clear that he was taught to count in an unusual way and even though it was different, it doesn't mean that it doesn't work for the needs they had. Also, it shows that he is capable of learning.