This question tests vocabulary related to 'distinction'. 'Distinction' primarily refers to a difference between two or more things. Option A, 'a similarity' is the opposite of a distinction. B, 'a difference' correctly describes what a distinction is. Option C, 'a connection' implies a link, which is not what a distinction is. Option D, 'a resemblance' indicates a similarity, thus is not a match for distinction. Key point is understanding that a distinction highlights what sets things apart, not what makes them similar. The correct answer is B.