 So, let's do this one. It says, which of the following alkenes is the most stable? So, what would be the name of the rule that you would want to follow to determine which alkenes most stable of here? Yes, it says rule. So, what does it say to rule? Tell us. Most stable ground is the most stable alkyne, right, is the most substitute. So, we're talking about substitutions around the what? Double bond. Double bond, okay. So, when we look at A here, how many substituents does it have around that double bond? Just two. Just two, right? So, the methyl group and the ethyl group. Why? Because hydrogens, we said, are not considered substituents, right? So, if we look, we've got two hydrogens and two substituents. What about here? Four substituents. Four substituents. So, let's just write that down. Two. Four. What about this one? Three. Three. This one? Two. Two. Okay, so which one's the most stable? Two feet. Why is that? Because it has the most substitutions. Okay, so that's the most stable. Any questions on that one? Okay, wonderful.