Choose the correct interrogative sentence :

Question

Accepted Answer

Option 4, "Had it been raining for long?" is the correct interrogative sentence. Here's why:

1. **Explanation for Option 4:**
   - This sentence correctly follows the structure of a past perfect continuous interrogative sentence in English. The structure for such sentences is: "Had + subject + been + present participle (verb+ing)?" 
   - In this case, "Had" is the auxiliary verb, "it" is the subject, "been" is part of the perfect continuous tense, and "raining" is the present participle. This structure is grammatically correct and clearly asks whether the action of raining had been occurring for a long time.

2. **Why the other options are incorrect:**

- **Option 1: "Had been it raining for long?"**
     - This option incorrectly places "been" before the subject "it." In English, the correct order in a question is "Had + subject + been," not "Had been + subject."

- **Option 2: "What been it had raining for long?"**
     - This option is grammatically incorrect and does not follow any standard English sentence structure. The words are jumbled, and it does not form a coherent question. "What" is not needed in this context, and the order of words is incorrect.

- **Option 3: "How had been it raining for long?"**
     - This option incorrectly uses "How" at the beginning, which is unnecessary for this type of question. Additionally, the word order is incorrect, as "had been" should not precede the subject "it" in this context.

In summary, Option 4 is the only choice that correctly forms a past perfect continuous interrogative sentence, adhering to the proper grammatical structure.