common law follows the past rulings of\no king john.\no judges.\no lawyers.\no william blackstone.

Brief Explanations:

Common - law is a legal system that relies on judicial precedents set by judges in past cases. Past rulings of judges form the basis for future decisions in common - law systems. King John is not related to the basis of common - law in this context. Lawyers are legal practitioners and not the source of past rulings for common - law. William Blackstone is a legal scholar who codified common - law but is not the source of the past rulings that common - law follows.

Answer:

B. judges