For a given material length, end conditions and equal area the shape of the column which is most efficient as per Euler’s is _________

For a given material length, end conditions and equal area the shape o

1.	For a given material length, end conditions and equal area the shape of the column which is most efficient as per Euler’s is _________
A.	Square
B.	Circular
C.	I section
D.	Tubular
Answer» E.