The most unsymmetrical crystal system is -
Cubic
Hexagonal
Triclinic
Orthorhombic
For triclinic crystal system
Seven crystal systems - On the basis of edge length and interaxial angle, crystal systems are of seven types- cubic, tetragonal, orthorhombic, monoclinic, hexagonal, triclinic, rhombohedral.
Therefore, Option (3) is correct.