The crystal system without any element of symmetry is

Triclinic crystal systems are the most asymmetrical, whereas cubic crystal systems are the most symmetric. A, B, C, and $\mathrm{a}\ne \mathrm{b}\ne \mathrm{c}\text{ and }\alpha \ne \beta \ne \gamma$ are the axial angles and distances that represent the triclinic system.

Therefore, the correct option is C triclinic