Step 1: Recall purpose of each test.
- (A) Plate load test: Used to estimate bearing capacity of soil for permissible settlement $\Rightarrow$ IV.
- (B) Standard penetration test (SPT): Used to estimate bearing capacity of granular soils $\Rightarrow$ I.
- (C) Vane shear test: Used to estimate in-situ strength of soft clay $\Rightarrow$ II.
- (D) Dilatancy test: Used to identify silt from clay $\Rightarrow$ III.
Step 2: Match them.
\[
A \to IV, B \to I, C \to II, D \to III
\]
Step 3: Conclusion.
Thus, the correct option is (3).


