The location of the Tehri Dam is commonly depicted on geographical diagrams or maps. The correct answer to this question is option 3, indicating that the Tehri Dam is located at the spot labelled `C`. To understand why the other options are incorrect, let`s dissect each of them:

Option 1 - `A`: This is incorrect because a different location is represented by `A`, it doesn`t correspond to the position of the Tehri Dam.

Option 2 - `B`: This doesn`t represent the Tehri Dam`s location either. The `B` site on the given figure refers to another spot.

Option 4 - `D`: `D` represents another separate geographical location on the diagram, thus it is also incorrect.

The only correct answer is option 3, `C`. This should be the labelled spot where Tehri Dam is situated according to the given figure.