4. A type of cast-in-situ pile which has an enlarged base and a corrugated stem, is
A. Franki pile
B. vibro-pile
C. Raymond pile
D. simplex pile
4. A type of cast-in-situ pile which has an enlarged base and a corrugated stem, is
A. Franki pile
B. vibro-pile
C. Raymond pile
D. simplex pile