Final answer:
The dependent variable in the experiment is what is being measured as the outcome, such as 'whether the picture was correctly classified or not' or 'the time it took participants to respond to each picture,' depending on the researchers' focus.
Step-by-step explanation:
In the context of an experiment, the dependent variable is the one that is being measured and is expected to change as a result of manipulating the independent variable. A dependent variable is essentially the outcome that researchers are interested in. Therefore, looking at your experiment options, a. 'whether the picture was correctly classified or not,' b. 'the race of each participant in the study,' c. 'the gender of the person appearing in the picture,' and d. 'the time it took participants to respond to each picture,' the dependent variable would likely be 'a. whether the picture was correctly classified or not' or 'd. the time it took participants to respond to each picture,' depending on what the researchers are specifically measuring as the outcome of their manipulation. The other options seem to describe characteristics of the participants or the conditions they are exposed to, which would typically be considered independent variables or controlled variables.