Which of the following represents a strong base? Now remember, certain group 1A and 2A metals need to be combined with a basic anion. We take a look at the options. Beryllium and magnesium are part of the certain types of group 1A or 2A metals. So A wouldn't be an answer, D wouldn't be an answer.
If we look at our remaining options, we have sodium, lithium and potassium. Yes, those are these certain types of group 1A metals that could potentially create a strong base if they combine with the right basic anion here. Sodium, if it combined with the oxide ion could make a strong base. But we have a problem. Remember, the numbers are different, so they crisscross 2 comes here. One comes here. Sodium oxide would actually be NA2O. This is not sodium oxide. This is actually sodium superoxide. It's not a strong base.
For the next one, we have lithium ion and it's combining with the amide ion, they give us lithium amide. So this is a strong base. It's the right group 1A metal with one of the basic anions in the form of the amide ion. And then finally E, we have potassium, which is good, but it's connected to hypoiodous acid. Hypoiodous acid does not represent one of our four basic anions, so this will not make a strong base.
So here the only answer that gives a strong base is option C in the form of lithium amide.