\( (a) \\ \mathrm{CoCl_3 \cdot 4 \\ NH_3} \)
\( (b) \\ \mathrm{CoCl_3 \cdot 5NH_3} \)
\( (C) \\ \mathrm{CoCl_3 \cdot 6NH_3} \) and
\( (d) \\ \mathrm{CoCl(NO_3)_2 \cdot 5NH_3} \)
Number of complex(es) which will exist in cis-trans form is/are __________.
