Answer: The correct answer is A: Falsifiability
Explanation: Falsifiability characterizes a theory, statement or model that can be proven wrong.
For a theory to be proven scientific it has to be falsifiable.
If a theory cannot be either proved or disproved it is not falsifiable and thus, cannot be considered scientific.
In this particular case, the levels-of-processing-model proposed by Craik and Lockhart (1972) does not have a way of scientifically being proven or disproven hence its falsifiability.
The correct answer is A.