Definition.
A writer would BEST DEVELOP a paragraph using a DEFINITION when he wants to get at the meaning of an abstract concept.
D) A savage beguiler
In sheathings of silk
The lines chosen must show that the sea is cruel but it seems as though it's not. The word beguile means to enchant something in a deceptive way. By describing the sea as a savage beguiler, it gives the sea the image of something that is fierce, but not seen as fierce. It's seemingly calm beauty, like silk, tricks one into thinking that it is calm.
The other options do not work. Option A only creates a negative image. Option B also only creates a negative image of the sea as a predator. Option C personifies the sea as having fingers, but doesn't show it's cruel nature.
Means that as long as your evil thoughts remain thoughts, then you won't be punished or thought less of by people.
But if your actions are evil, then you will be punished and considered evil by other people, even if your intentions weren't evil (although perhaps get a lesser sentence in court).