student conducted an experiment to whether talking to plants would help them to grow faster. He set up the following two groups: Group 1: spoken to and hand watered Group 2: not spoken to and watered with sprinklers After three weeks, the plants in Group 1 showed much more growth than those in Group 2. Based on the results of this experiment, which is the best conclusion? I because the student ran a controlled experiment They are not valid because the student did not control all the variables that can affect plant growth. They are valid because the dependent variable caused a change in the independent variable. They are not valid because the time frame to grow a plant is too short.

Based on the information provided, the best conclusion is that the results of the experiment are not valid because the student did not control all the variables that can affect plant growth.<br /><br />In a controlled experiment, all other factors should be kept constant except for the independent variable being tested. In this case, the independent variable is whether the plants are spoken to or not. However, there are other factors that can affect plant growth, such as the amount of water, type of water delivery system, light exposure, and soil quality. Without controlling these variables, it is difficult to determine if the growth difference between the two groups is solely due to talking to the plants or if it is influenced by other factors.<br /><br />Therefore, the conclusion that the results are not valid because the student did not control all the variables that can affect plant growth is the most accurate.