Correct option - b
The transactions under B to C are between business firms and consumers.
Explanation:
B to C, i.e., business to consumer, refers to commercial transactions between business firms and consumers. Other types of transactions include, C to C, i.e., consumer to consumer, which refers to commercial transactions that take place between consumers. B to B, i.e., business to business, refers to business transactions that take place between two business firms.