Which of the following system is not correctly characterized?
| A. |
cubic: a=b=c; `alpha=beta=gamma=90^o` |
| B. |
tetragonal: `a=b!=c`; `alpha=beta=gamma=90^o` |
| C. |
orthorhombic: `a!=b!=c; alpha=beta=gamma=90^o` |
| D. |
rhombohedral: `a=b!=c; alpha=beta=gamma=90^o` |
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