Option 1: Enforceable in the courts of law - This means that the directive principles can be directly enforced through legal action. However, this is not the case. The directive principles are not enforceable in the courts of law, meaning that citizens cannot directly take legal action to enforce them.

Option 2: Quasi-enforceable - This means that the directive principles have some degree of enforceability, but not to the same extent as fundamental rights. However, this is also not the case. The directive principles are not quasi-enforceable.

Option 3: Partly non-enforceable - This means that some of the directive principles are enforceable, while others are not. This is incorrect. The directive principles are as a whole non-enforceable.

Option 4: Non-enforceable in the courts of law - This is the correct answer. The directive principles are non-enforceable in the courts of law, meaning that they are not legally binding and cannot be directly enforced through legal action.