Pablo and Johanna have to do a yearlong study for their biology course. After some discussion, they decide to try comparing their dogs and the diet that they feed them. Each has a dog from the pound, and both dogs are less than one year old. Pablo feeds his shepherd-mix dog a special diet of wet and dry foods from the local vet, while Johanna uses generic dry kibble from the supermarket for her bulldog. They want to see which diet results in bigger, healthier, faster-growing dogs. The reason the instructor gives them will include the fact that they have too many

The correct answer is - variables that they didn't control and not enough replicates

Explanation:

In this particular case, Pablo and Johanna using too many variables in their experiment or research, All the variables used, are not controlled and with time these variables can not be replicated again on experiment groups.

They did not select a particular age or weight of dogs, the diets are different and they feed dry kibble to only one dog. There are so many variables and for a better result experiment, all variables should be controlled only the independent variable is permitted to manipulate.

answer; i believe its echoic memory,it is believed to last three to four seconds; good luck

option c is the correct answer.