Only inherited differences that can be passed on are acted upon evolution.

Only inherited traits differences that can be passed on are acted upon evolution.

In the study, the humans select desirable traits that can be passed from one generation to another.

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.