Which of the following are the correct axial distance and axial angles for rhombohedral system ?

Which of the following are the correct axial distance and axial angles

1.	Which of the following are the correct axial distance and axial angles for rhombohedral system ?
Answer» `a = B = C, alpha = beta = gamma != 90^(@)` `a = b != c, alpha = beta = gamma = 90^(@)` `a!= b != c, alpha = beta = gamma = 90^(@)` `a != b != c, alpha != beta != gamma != 90^(@)` ANSWER :A