Step 1: Understanding the question.
The question deals with grammatical cases used to denote relationships between nouns and verbs in a sentence. Specifically, it asks which case represents the “instrument” or “means” by which an action is performed.
Step 2: Explanation of options.
- (1) Dative Case: Refers to the indirect object or recipient of an action (e.g., “to him”).
- (2) Ablative Case: Indicates separation or movement away from something.
- (3) Instrumental Case: Denotes the means or instrument by which an action is carried out — correct answer.
- (4) Vocative Case: Used for addressing or calling someone directly.
Step 3: Example.
In the sentence “He wrote with a pen,” the phrase “with a pen” shows the instrument used. Hence, it is in the Instrumental Case.
Step 4: Conclusion.
Therefore, the correct answer is (3) Instrumental Case.