Step 1: Understanding the Concept.
The passage uses exactly one case, a single killer's behaviour, to support a sweeping claim about the death penalty's effect on deterrence in general.
Step 2: Check option A.
The argument does not lean on emotionally charged language or appeals to sympathy or outrage; it presents a case as evidence, so it is not primarily an appeal to emotion.
Step 3: Check option B.
There is no comparison being drawn between two different situations that are then treated as alike, so this is not an analogy at all.
Step 4: Check option D.
The conclusion is not simply a restatement of the premise in different words, so this is not circular reasoning.
Step 5: Check option C.
One murderer's choice to move to a death-penalty state and then kill is used as if it proves something about deterrence everywhere, which is exactly a general conclusion drawn from a single specific example.
Step 6: Final Answer.
Option C best characterises this argument.