which of the following projections of the abdomen may be used to demonstrate air or fluid level

which of the following projections of the abdomen may be used to demonstrate air or fluid level?
1. dorsal decubitus
2. lateral decubitus
3. AP trendelenburg
a. one only
b. 1 and 2 only
c. 1 and 3 only
d. 1,2 and 3