Answer: Option D
Step-by-step explanation:
The passive transport can be defined as the process by which the ions and other atomic molecular substances across membrane without the need of energy.
Energy is not required during the process of passive transport because the the molecules or ions move from a region where it is having more concentration to a region where it has a less concentration.
Energy is required in the movement of the ions or molecules against the concentration gradient.
This is why the passive movement of molecules does not requires energy.