In a triclinic crystal system,which of the following conditions is true?

• A
  $a \ne b \ne c$,$\alpha \ne \beta \ne \gamma \ne 90^{\circ}$
• B
  $a = b = c$,$\alpha \ne \beta \ne \gamma$
• C
  $a \ne b \ne c$,$\alpha \ne \beta = \gamma$
• D
  $a = b \ne c$,$\alpha = \beta = \gamma = 90^{\circ}$