The karez well system
a.
was the first known use of wells
b.
was a postindustrial system
c.
transported groundwater from a distance
d.
all of the above

option C

Explanation:  The Kanez wells accounts for about 30% of the total irrigation areas in the Turfan area.

The length of these wells varies with the geographical environment. It mainly consists of 4 parts the open channel, vertical well, small reservoir and underground channel.

The water outlet for the underground water is called as the dragon mouth which is in connection with the channels above ground. This transports the groundwater from a distance.

the answer to this question is a