Going through the options, we can cross out the wrong options.
Option 1:
Expected values:
These are the values with which we are trying to compare with the observed values from the data.
Hence, the researcher does need to pay attention to this since it is critical to calculating the chi square statistic for the research, which would determine whether or not there's a dependence in the data.
Option 2:
Norminal data:
This is just referring to data that is not ordered and categorical. The question already mentions that the data is categorical, hence, it is not significant.
Option 3:
Measures are independent of each other:
The measures being independent of each other is in fact what the chi-square is used to find.
As such, this cannot be a factor when carrying out the test when it is in fact a possible outcome
Option 4:
Number of groups:
The number of groups under consideration for the test is not a factor to consider, since we
have been told the data is limited and chi-squared is used to find independence or dependence between two groups.
Hence, the final answer is: Expected Values (Option 1)