The direction of the conduction of food through phloem is

According to the pressure flow hypothesis:
$A.$ Phloem loading produces a hypertonic condition in the sieve tubes.
$B.$ Water potential gradient facilitates the mass movement in the phloem.
$C.$ Phloem unloading is a passive process.

In a ring girdled plant,

In sieve tubes, the maximum hydrostatic pressure is found to be: (in $bars$)

The food stored in the ripening fruit is derived from

$A$ few drops of sap were collected by cutting across a plant stem by a suitable method. The sap was tested chemically. Which one of the following test results indicates that it is phloem sap?