Compound (A) reacts with `[Cu(NH_3)_2]^(+)` and Tollens reagent, but after with alc: KOH it does not give the above test. Compound (A) is:

Options

A. (a) `Me--=-Me`
B. (b) `Me--=-H`
C.
D. (d) `Ph--=-H`

Explanation

To solve the question, we need to analyze the behavior of compound (A) with the reagents mentioned: `[Cu(NH_3)_2]^(+)` (which is a copper(II) complex) and Tollens' reagent, and then its behavior with alcoholic KOH.

### Step-by-Step Solution:

1. **Identify the Reagents and Their Reactions**:
- The compound (A) reacts with `[Cu(NH_3)_2]^(+)` and Tollens' reagent. Both of these reagents are known to react with terminal alkynes.
- The reaction with `[Cu(NH_3)_2]^(+)` produces a red precipitate (copper(I) acetylide), and the reaction with Tollens' reagent produces a white precipitate (silver acetylide).

2. **Determine the Structure of Compound (A)**:
- Since compound (A) reacts with both reagents, it must be a terminal alkyne. Terminal alkynes have the general structure R-C≡C-H, where R is an alkyl group.

3. **Analyze the Reaction with Alcoholic KOH**:
- The question states that after treatment with alcoholic KOH, compound (A) does not give the above tests. Alcoholic KOH can lead to elimination reactions, converting terminal alkynes to internal alkynes.
- If compound (A) is a terminal alkyne, treatment with alcoholic KOH could convert it into an internal alkyne, which would not react with `[Cu(NH_3)_2]^(+)` or Tollens' reagent.

4. **Consider the Options**:
- We need to evaluate the given options (not provided here) to identify which one is a terminal alkyne that can be converted to an internal alkyne upon treatment with alcoholic KOH.

5. **Conclusion**:
- Based on the analysis, the correct compound (A) must be a terminal alkyne that, upon treatment with alcoholic KOH, forms an internal alkyne. This is consistent with the behavior described in the question.

### Final Answer:
The compound (A) is a terminal alkyne that converts to an internal alkyne upon treatment with alcoholic KOH.