Which of the following represents the possible structure of a base? So remember bases can either be ionic bases or they can be covalent bases. For the first one we have C4H all right. So if we take a look at this, this would not be an ionic basin that doesn't have a metal cation involved, it's only non metals there. And it wouldn't be a neutral base either because it's not an amine. So this would not be an answer.

BB isn't a mean because it's composed of nitrogen and hydrogen. But remember, typically we're going to say the neutral means are what's going to be classified as a base. Positive means we've talked about before in earlier videos. Positive means are typically acidic, so this would not work.

C is an answer because in C we have potassium which is a metal connected to hydroxide ion. See it was K+ and OH- that combined to give us potassium hydroxide.

Then finally, D doesn't work because D is a covalent compound that begins with the hydrogen, which is a simple way of looking at this being an acid. Out of all the choices only options, C represents atypical base.