In a certain code, 'PURE' is written as
'QVQD' and 'COPE' is written as
'DPOD', then 'WHEN' is written as :

Question

In a certain code, 'PURE' is written as
 'QVQD' and 'COPE' is written as
 'DPOD', then 'WHEN' is written as :

Accepted Answer

To solve the problem of determining how 'WHEN' is encoded in the given code, we need to first understand the pattern used in the examples provided: 'PURE' to 'QVQD' and 'COPE' to 'DPOD'.

### Step-by-Step Explanation:

1. **Analyzing the Code Pattern:**
   - **PURE to QVQD:**
     - P to Q: The letter P is shifted forward by 1 position in the alphabet.
     - U to V: The letter U is shifted forward by 1 position.
     - R to Q: The letter R is shifted backward by 1 position.
     - E to D: The letter E is shifted backward by 1 position.

- **COPE to DPOD:**
     - C to D: The letter C is shifted forward by 1 position.
     - O to P: The letter O is shifted forward by 1 position.
     - P to O: The letter P is shifted backward by 1 position.
     - E to D: The letter E is shifted backward by 1 position.

2. **Identifying the Pattern:**
   - The pattern involves alternating shifts: the first two letters are shifted forward by 1 position, and the last two letters are shifted backward by 1 position.

3. **Applying the Pattern to 'WHEN':**
   - W to X: Shift W forward by 1 position.
   - H to I: Shift H forward by 1 position.
   - E to D: Shift E backward by 1 position.
   - N to M: Shift N backward by 1 position.

4. **Result:**
   - Following the pattern, 'WHEN' is encoded as 'XIDM'.

### Explanation of Options:

- **Option 1: XIFO**
  - Incorrect because the third letter should be D, not F.

- **Option 2: XDIM**
  - Incorrect because the second letter should be I, not D.

- **Option 3: XIDM**
  - Correct because it follows the identified pattern accurately.

- **Option 4: XIMD**
  - Incorrect because the third letter should be D, not M.

Thus, Option 3, 'XIDM', is the correct answer as it accurately follows the encoding pattern established by the examples.