Convert the sentence provided below from its passive voice structure to an active voice structure:
The cake was baked by Mary for her brother's birthday party.

Correct option is C

The correct active/passive voice of the given sentence is (c).
Explain the rules of conversion from passive to active with structure in detail.
When a sentence is in simple past passive (was/were + V3), convert to simple past active (Subject + V2 + Object). The agent in the “by”-phrase becomes the subject in active voice; the passive subject becomes the object.
Structure:
· Passive Voice: Object (The cake) + was + V3 (baked) + by + Agent (Mary) + Adverbial (for her brother's birthday party).
· Active Voice: Agent (Mary) + V2 (baked) + Object (the cake) + Adverbial (for her brother's birthday party).
· Thus, “ Mary baked the cake for her brother’s birthday party.”
· Information booster: The adjunct “for her brother’s birthday party” remains unchanged. If the agent is unknown/irrelevant, the by-phrase is often omitted in passive constructions.