Step 1: Understanding the Question:
This question tests knowledge of watershed characteristics.
Step 2: Detailed Explanation:
Two contiguous watersheds may have different characteristics based on topography, soil, land use, and drainage.
They are not necessarily similar.
Thus, Statement I is incorrect.
Each watershed unit is a well-defined topographically delineated area with a distinct boundary.
This is the definition of a watershed.
Thus, Statement II is true.
Therefore, Statement I is incorrect but Statement II is true.
Step 3: Final Answer:
Thus, Statement I is incorrect but Statement II is true, which corresponds to option (D).
[0.5cm]