A sentence has been given in Active Voice. Out of the four given alternatives, select the one which best expresses the same sentence in Passive Voice. Active Voice: The cat teased the rat.

Introduction / Context:
Voice change questions check whether a learner can correctly transform a sentence from active to passive voice or vice versa while preserving tense, meaning, and grammatical correctness. The given sentence "The cat teased the rat" is in the simple past tense and uses a transitive verb "teased" which allows a passive construction.

Given Data / Assumptions:

• Active sentence: "The cat teased the rat."
• Subject in active voice: "The cat".
• Object in active voice: "the rat".
• Verb: "teased" (simple past).
• We assume standard rules for forming passive voice in simple past tense.

Concept / Approach:
To convert a simple past active sentence into passive voice, we follow a clear pattern. The object of the active sentence becomes the subject of the passive sentence. The helping verb "was" or "were" is used according to the new subject, followed by the past participle of the main verb. Finally, the original subject appears in a prepositional phrase introduced by "by". So the structure is: Object + was/were + past participle + by + subject.

Step-by-Step Solution:
Step 1: Identify the object and subject in the active sentence. "The cat" is the subject, "teased" is the verb, and "the rat" is the object. Step 2: Move the object "the rat" to the beginning of the passive sentence as the new subject. Step 3: The tense is simple past, so use "was" for a singular subject like "the rat". Step 4: Convert "teased" into its past participle form, which is also "teased". Step 5: Add "by the cat" to show the original doer of the action. Step 6: The resulting sentence is: "The rat was teased by the cat." Step 7: Check which option matches this exactly: Option B.

Verification / Alternative check:
Now examine each option quickly:
Option A: "The rat is teased by the cat." This is in simple present tense, not simple past, so the tense does not match the original sentence. Option B: "The rat was teased by the cat." This is in simple past passive and preserves the original meaning. Option C: "The rat got tease by the cat." This is grammatically wrong; it should be "got teased" if we were using that structure. Option D: "The rat was subject to teasing by the cat." Although roughly similar in meaning, it changes the structure and introduces a noun form "teasing", which is not the standard direct passive transformation. This confirms that Option B is the best and most accurate passive form.

Why Other Options Are Wrong:
Option A: Incorrect tense (present instead of past) and therefore does not faithfully represent the original sentence. Option C: Contains a grammatical error in the verb phrase "got tease" instead of "got teased". Option D: Uses a different construction, changing the verb into a noun phrase and altering the direct voice transformation that exams usually require.

Common Pitfalls:
Learners sometimes overlook tense when changing voice and focus only on rearranging subject and object. Others may think that a sentence with a similar idea is acceptable, even if the grammatical form is quite different. In exams, however, you must preserve both tense and meaning as closely as possible. It is helpful to memorise the standard passive patterns for each tense and practise them with simple example sentences until the transformation becomes automatic.

Final Answer:
The correct passive voice form of the sentence is "The rat was teased by the cat."