Water will be absorbed by root hairs when the external medium is hypotonic. This kind of absorption takes place passively. The water can easily move from the region of higher concentration to the low concentration without expenditure of energy by facilitated diffusion through the aquaporins. Water is absorbed by the root hair from the soil. It passes the epidermis, cortex, endodermis, casparian strip and pericycle and protoxylem and metaxylem.

So, the correct answer is option C.