Step 1: Understand the profile types.
The profiles S\(_1\), S\(_2\), and S\(_3\) describe different types of flow profiles based on the slope change. S\(_3\) is typically the profile that occurs when the slope changes from steeper to less steep.
Step 2: Identify the correct profile.
The correct profile for a change from a steeper slope to a less steep slope is S\(_3\).
Final Answer: (A) S\(_3\)

| Point | Staff Readings Back side | Staff Readings Fore side | Remarks |
|---|---|---|---|
| P | -2.050 | - | 200.000 |
| Q | 1.050 | 0.95 | Change Point |
| R | - | -1.655 | - |