Read the passage.

Research on people’s purchasing habits was conducted by researchers at the firm. The team prepared dozens of questions to ask participants. The participants answered these questions for the researchers. The researchers carefully examined the findings to determine trends.

In order to make his writing more effective, Shane is changing verbs in passive voice to active voice. Which sentence needs to be changed to active voice?

Research on people’s purchasing habits was conducted by researchers.
The participants answered these questions for the researchers.
The team prepared dozens of questions to ask the eager participants.