Figure 4.23A -The Structures Labeled "D" in the Accompanying Figure _____

Multiple Choice

Figure 4.23A

-The structures labeled "D" in the accompanying figure _____.

A) ​prevents movement of materials between cells
B) ​allows passage of a signal to contract heart muscles
C) ​allows the free passage of materials between cells
D) ​is found mostly in stomach tissue
E) ​is found in most tissues except heart muscle