Robert hits his kindergarten teacher to get his attention even though the teacher is busy with other children. the teacher documented that this happens eight times a day. this child's challenging behavior is most likely rooted
a. having to do to many homework pages
b. not knowing how to get the teachers attention properly
c. a lack of sleep
d. having a fully developed optical connection

B) Not knowing how to get the teachers attention properly

Explanation:

It is very normal for small children, and several adults also, to not know how to properly get the attention of other people, specially those very relevant, significant or important individuals. A teacher is very important for a small child, and small children also have a tendency to be easily frustrated (again similarities with adults are only a coincidence).

Since Robert doesn't know how to get his teacher's attention, he gets frustrated and starts hitting her, because he doesn't know what else to do.