Answer:
Transcellular.
Step-by-step explanation:
The transportation of solutes and water occurs in the proximal convoluted tubule. The transport of solute occurs mainly via the two routes of transport known as paracellular transport and transcellular transport.
Transcellular transport may be defined as the transport by the cell through the cell. This process requires the energy for the transportation of molecules across the cells. The solutes are transported through the cell and most common route of transfer present in the proximal convoluted tubule.
Thus, the correct answer is option (a).