Which of the following systems is not correctly characterised ?

Options

A. cubic : `a=b =c,alpha=beta=gamma=90^(@)`
B. tetragonal : `a=b ne c,alpha=beta=gamma=90^(@)`
C. orthorhombic : `a ne b ne c,alpha=beta=gamma=90^(@)`
D. rhombohedral : `a=b ne c,alpha=beta=gamma=90^(@)`

Answer

D