Class lecture discussed research conducted in China on infants' ability to recognize their mother's voice 1 or 2 weeks before the infants were born. In one condition, infants heard their mother's voice reading a poem. This research was appropriately conducted because, in the second condition, infants heard:

another woman reading the same poem

Explanation: For a  research to be appropriately conducted, it must be valid and reliable,  Scientists include a control or more than one conditions for analysis to make sure the results of their experimental research can be  compared between the main measurements and the control measures or other conditions  in order to increase the reliability of the outcomes and make their research valid.

Here to make the research valid, a first condition which involved the infants hearing  their mother;s voice and the second condition which , infants heard another woman voice reading the same poem are being conducted to draw reasonable conclusions whether infants can identify their mother through voice.

a is the final ! : )