Drilling mud .
Choose one:
A. decreases the surface tension of the oil in the drill hole and can sometimes cause gushers.
B. is a slurry of water and sand.
C. is used to cool the drill bit and to flush rock cuttings up and out of the drill hole.
D. is created when the drill bit scratches and gouges out the rock.

Option C.    Is used to cool the drill bit and to flush rock cuttings up and out of the drill hole

Explanation:

Drill mud plays a vital role in the drilling process. Its addition into the well-bore does a lot in enhancing the drilling processes and activities.

Among other importance and function of the drill mud /fluid:

1.  It is used to cool off the drill bit

2.  It flushes rock cuttings out of the drill hole

3.   High pressure control

4.  Providing buoyancy

5.  Lubrication

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