Choose the best tense to complete the sentence: Sita was cooking in the kitchen when her husband _____ the bell.

Introduction / Context:
This grammar question checks your understanding of tense consistency in complex sentences with two actions happening in the past. The sentence is about an ongoing action being interrupted by another action: “Sita was cooking in the kitchen when her husband was ringing the bell.” You must select the best replacement for the underlined part to make the sentence natural and correct in standard English.

Given Data / Assumptions:

• Main clause: “Sita was cooking in the kitchen …” (past continuous tense, describing an action in progress in the past).
• Subordinate clause: “when her husband was ringing the bell.”
• Only one answer choice provides the appropriate tense and aspect for the second action.
• We assume a typical competitive exam pattern where the focus is on correct tense usage in narrative sentences.

Concept / Approach:
In English narratives, the past continuous tense is often used for an action that was already in progress, and the simple past tense is used for an action that suddenly occurred and interrupted or happened during that ongoing activity. The standard pattern is “was/were doing something when something happened”. Therefore, one clause remains in the past continuous, while the other uses the simple past. Using past continuous in both clauses usually sounds unnatural and is rarely required unless both actions are parallel and continuous.

Step-by-Step Solution:
Step 1: Identify the ongoing action. Sita was cooking in the kitchen. This is an action in progress, properly expressed by “was cooking”. Step 2: Identify the second action. Her husband rang the bell at a specific moment in time. This is a shorter, completed action that interrupts the ongoing activity. Step 3: Apply the rule: ongoing past action + sudden past action is usually written as “was/were + verb-ing” in one clause, and simple past (verb in past form) in the other clause. Step 4: Replace “was ringing” with a simple past form. Option C “rang” is the correct simple past form of “ring”. Step 5: The improved sentence becomes “Sita was cooking in the kitchen when her husband rang the bell.” This is grammatically correct and idiomatic.

Verification / Alternative check:
Compare with similar examples: “I was reading when the phone rang”, “They were playing when it started to rain”, “We were having dinner when the lights went out”. In each case, the structure is past continuous + simple past. If we change the second verb to past continuous (“was ringing”, “was starting”, “were going out”), the sentences sound awkward and suggest a long, drawn-out action instead of a brief event. This confirms that “rang” is the right choice here.

Why Other Options Are Wrong:
“would have been ringing”: suggests a hypothetical or conditional past, which does not fit the simple narrative context. “had rung”: indicates past perfect, usually used to show that one past action happened before another past action; however, here the bell ringing occurs during the cooking, not before it. “No improvement”: keeps “was ringing”, which is grammatically possible but stylistically wrong for this typical exam pattern and does not express the momentary interruption clearly.

Common Pitfalls:
Learners often get confused between past continuous and past perfect tenses. They sometimes overuse past perfect (“had rung”) whenever there are two past actions, even when the relationship is not “earlier vs later” but “ongoing vs interrupting”. Another common mistake is to put both verbs into past continuous when exam questions specifically test the interrupted-action pattern. Remember: if one continuous activity is interrupted by a short action, the continuous form stays for the longer action and the simple past is typically used for the shorter one.

Final Answer:
The correct improvement is rang, giving the sentence “Sita was cooking in the kitchen when her husband rang the bell.”