Explain why the number of squid might change if there were a significant decrease in the number of cod?

pls answer

In the given food web, squid depends on cod, krill and small animals for food. Squid gets sufficient to food to eat from three sources, hence they reproduce and number of squid in the ecosystem is increasing. If there were a significant decrease in the number of cod, then only two food sources would be available for squid. In this situation the number of squid will decrease in absence of sufficient food.

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.