Full node storage requirements for new 2MB block which is only 10% full If blocks were 2MB, and a 2MB block that is only 10% full gets confirmed, then how much additional storage is required on a full node?

I am guessing the correct answer here is 200K?

Thanks in advance for any guidance in this matter.
Full nodes are not required to store blocks (they can be pruned). So the answer is 0.

If a 200 kB block does get stored, it takes 200 kB to store it.