Please choose the correct answer to the question: The cows in a rancher's herd of cattle have been selectively bred to produce milk. Which of the following will cause the next generation of cows to receive the trait for producing large quantities of milk?

Answer1: nutrients in the cows' food Answer2: essential minerals in the cows' water Answer3: electrical impulses in the cows' brains Answer4: information in the cows' chromosomes

Answer format: answer1/answer2/answer3/answer4
Answer: answer4