Answer:
B. a volcanic mudflow that resembles fluid concrete.
Step-by-step explanation:
Lahar -
Lahar is a form of debris or mud , basically made up of water , rocky debris and slurry .
Lahar are very devastating in nature as it flows out from the volcano along the river .
The characterstics of Lahar is , it is very large , and dense and viscous in nature .
One of the example if Lahar is ,
The Osceola Lahar , originated from the volcano of Mount Rainer in United states , specifically in the aresa of Washington , it covered the area of about 330 square kilometres , with a volume of about 2.3 cubic kilometres .