Step 1: Understanding the Concept:
Voice conversion in English is the process of changing a sentence where the subject performs the action (Active Voice) into a sentence where the subject receives the action (Passive Voice).
When dealing with complex sentences—those containing multiple clauses joined by a conjunction—the rule of thumb is to convert every clause containing a transitive verb into its passive equivalent to maintain stylistic consistency.
In this specific sentence, we encounter two distinct verbal structures: a semi-modal of obligation (``have to'') and a modal of capability (``can'').
Each requires a specific formula for passive transformation while ensuring that the tense remains unchanged and the new subjects agree in number with their respective verbs.
Step 2: Detailed Explanation:
Let's analyze the sentence by dissecting its two primary components:
Clause 1 (Active): ``They have to paint the ceiling...''
- Subject: ``They'' (Plural)
- Verb: ``have to paint'' (Semi-modal + Base Verb)
- Object: ``the ceiling'' (Singular)
To transform this, we move ``the ceiling'' to the subject position. The passive rule for ``have to'' is: New Subject + has/have to + be + V3.
Since ``the ceiling'' is singular, ``have to'' must change to ``has to''. This gives us: ``The ceiling has to be painted...''
Clause 2 (Active): ``...before they can install the new light fixtures.''
- Subject: ``they''
- Verb: ``can install'' (Modal + Base Verb)
- Object: ``the new light fixtures'' (Plural)
The passive rule for modals is: New Subject + Modal + be + V3.
Moving the object to the front, we get: ``...before the new light fixtures can be installed.''
Evaluating Distractors:
- Option (B) is incorrect because it retains the plural verb ``have'' for the singular subject ``ceiling'' (Subject-Verb Agreement error).
- Option (C) is ungrammatical because ``fixtures can install'' suggests the fixtures are performing the installation themselves.
- Option (D) changes the semi-modal ``have to'' into ``must''. While the meaning is similar, a precise voice conversion should preserve the specific verb used in the active sentence.
Step 3: Final Answer:
Combining both correctly transformed clauses leads us to Option (A), which perfectly maintains the tense, meaning, and grammatical agreement of the original sentence.