Answer:
The correct answer is
Both (b) and (c) are correct
Step-by-step explanation:
A pure public good also called social or collective good, is one that is perfectly non-rivalrous in consumption and is non-excludable.
Non-rivalrous: This means that everyone has access to such goods and the use of these goods by one person does not deplete its availability to the others. An example is a streetlight or a lighthouse.
Non-excludable: A good is non-excludable if non-paying consumers cannot be prevented from having access to their usage. An example is air.