When Electron Micrographs Were First Taken of the Cell Interior,what

Multiple Choice

When electron micrographs were first taken of the cell interior,what kinds of membranous structures were seen?

A) membrane-bound vesicles of varying diameter,containing material of different electron density
B) long channels bounded by membranes and radiating through the cytoplasm
C) an interconnected network of canals
D) stacks of flattened,membrane-bound sacs called cisternae
E) All of these are correct.