Movement of Phloem Sap from a Source to a Sink

Movement of phloem sap from a source to a sink ________.

A) occurs through the apoplast of sieve-tube elements
B) depends upon active transport of sugars into the sieve-tube elements
C) depends on tension, or negative pressure potential
D) depends on active transport of water into sieve-tube elements at the source
E) results mainly from diffusion of sugars into companion cells