The stability of a conformation depends on the steric strain and torsional strain. In chair conformations, bulky substituents prefer equatorial positions to minimize steric strain. The correct conformation in this case is the one where bulky groups are in the equatorial positions.
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:
\[
\boxed{\text{(1)}}
\]