The answer is "C", "as similar as possible".
Applying the relevant rule of law to the facts of a case regularly requires finding beforehand decided cases that, in response to the case under thought, are as similar as could be expected under the circumstances. Dissimilar to most civil law frameworks, common law frameworks take after the method of stare decisis, by which most courts are bound by their own particular past decisions in comparative cases, and all lower courts, should choose decisions complying with past decisions of higher courts.