C is the odd row out.

In A two letters are skipped between each letter.
In B three letters are skipped between each letter.
In C four letters are skipped between each letter except V, which should be U.
The numbers in rows D, E and F follow the same pattern.

The water level remains unchanged because the ice cube displaces its own weight. If you’re not convinced, read Archimedes’ Principle, which states that any floating object displaces its own weight of fluid. Still not convinced? Here are a few more sources.

Lemonade. It’s the only drink in the list.

5 owls and 5 wolves, (not 6 owls because 2 of the eyes and legs are yours).

2 * owls + 2 * wolves = 20 eyes
2 * owls + 4 * wolves = 30 legs
owls + wolves = 10 eyes → owls = 10 – wolves
owls + 2 * wolves = 15 → 10 – wolves + 2 * wolves = 15 → wolves = 5
owls + 5 = 10 → owls = 5

Uncopyrightable, with 15 letters and not a single one repeated. Dermatoglyphics, the study of fingerprints, works too.

“new door” can be rearranged into “one word”