Which of the following does not require carrier molecules during transport through cell membranes?

Active transport of solute in plants refers to the flow of solutes against a concentration gradient and therefore requires an input of energy. This energy is derived:

$A$ plant with well-washed roots was placed in a beaker of water diluted with red ink. The red colour travelled up the stem and into the leaf veins. Which of the following is the explanation for the uptake of red ink into the roots?

In a .....$A$..... both molecules cross the membrane in the same direction,in an ...$B$.... they move in opposite direction :
$A - B$

$A-$ In an antiport,both molecules move in opposite directions.
$R -$ In symport,only one molecule crosses the membrane in the same direction.

Which of the following processes does not occur against the concentration gradient?