Read the excerpt from A Short Walk Around the Pyramids and through the World of Art. In the past, the Kota spoke to the bones of their ancestors before making important decisions. They stored the bones in small baskets woven of rolls of bark or leaves. Sculpture such as this piece -- which is called a Kota funerary figure -- was tied to the top of the baskets. We are not certain what the figure meant to the Kota.

Which text feature would best help the reader understand this excerpt?

a sidebar about other African tribes
a glossary to define the word "funerary"
a graph showing the number of Kota sculptures
a chapter heading to summarize the text