Question 1
Why can a pressure applied at one place in a liquid be transmitted to another place in it?
The right answer is the one marked above.
Because liquids cannot be compressed. With no room to be squeezed, the applied pressure passes through the liquid undiminished.
Taking the shape of the vessel is a property of liquids, but it is not the reason. A gas does that too, yet a gas can be compressed, so pressure is not transmitted through it in this way.