Step 1: Analyze Each Conformation.
- In option (1), the bulky groups (represented by methyl or other groups) are in equatorial positions, minimizing steric interactions. This will be the most stable conformation.
Final Answer: \[ \boxed{\text{(1)}} \]
The spin-only magnetic moment of \([Co({H}_2\text{O)}_6^{2+}]\) (rounded off to one decimal place) is \(\underline{\hspace{2cm}}\) BM.