Please choose the correct answer to the question: A group of students investigated the effect of water temperature on the gill movements of goldfish. The students tested water temperatures from 20°C to 10°C at 2-degree intervals. The data showed that as water temperature decreased, the average number of gill movements per minute by the goldfish also decreased. Which type of display is BEST used to show this relationship?

Answer1: a bar graph Answer2: a pie chart Answer3: a line graph Answer4: a tally chart

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