Which compound is most likely a powerful and dangerous acid?

Here's a list of 4 acids that are considerably more dangerous, including one that dissolves your body from the inside-out and another that eats through solids like the corrosive blood of the creature in the Alien 

the moon affects the earth gravitation ally, causing certain motions of that body and also producing tides in its ocean and atmosphere. the tidal wave in our atmosphere is, however, far too minute to be an effective cause in any known meteorological phenomenon.

explanation: