A study examining the relationship between humor and memory compares memory performance scores for one group presented with humorous sentences and a second group presented with nonhumorous sentences. The participants presented with the humorous sentences are all males. The participants presented with the nonhumorous sentences are all females. In this study, gender (male/female) is best characterized as a(n) variable.

- Extraneous.

Explanation:

'Extraneous' variable is demonstrated as an undesirable or unwanted variable as they are being studied unintentionally. An experiment primarily comprises of two variables dependent and the independent. The independent variable is manipulated to observe its impact on the dependent variable while the other variables that come in contact during the experiment unintentionally would be regarded as the extraneous variables.

In the given example, the gender would be characterized as 'extraneous variables' because it is not being studied and thus, does not have a direct role to play in the experiment and characterized as undesirable. Here, gender has no much association with the relationship between humor and memory but may cause an effect on the variables that are being studied(humor and memory). Therefore, the 'extraneous' variable is the correct answer.