Answer:
b. Directory listings
Step-by-step explanation:
Directory listings -
It refers to the method of advertising , where the previous information of the consumers are used in order to provide them information about some new product or plan , is referred to as the directory listing .
It is a very inexpensive method of advertising .
And a particular group of consumers are targeted while promoting the goods and services .
Hence , from the given information of the question ,
The correct answer is b. Directory listings .