For the crystal class, which one of the following statements is correct?
(a) If a restraint is imposed on the growth of crystal, it will have an external symmetrical shape only
(b) The molecules are arranged in an irregular manner but in a repetitive pattern.
(c) The shape will be symmetrical only if it possesses all the elements of symmetry
(d) The shape will be symmetrical only about a plane if it divides the shape in two identical halves.