The sentence that uses active voice is: "The students organized the bake sale." In this sentence, the subject (students) is performing the action of organizing.
The other sentences provided are examples of passive voice or contain errors. For example:
- "The bake sale was organized by students." (passive voice)
- "It was decided that since were organized a bake sale." (incomplete and unclear)
- "It was a student who organize the bank cell." (active but contains grammatical errors)
The correct active voice should be "It was a student who organized the bake sale."