Answer:
b. a Ponzi scheme.
Step-by-step explanation:
Ponzi scheme -
It is basically a fraud investing scheme , which promise very high return rates with very less risk to the investors .
This scheme generates returns for the early investor by enabling new fresh investors .
People , who need money , generally take this path way , and lose even the amount with them .
This scheme is same as the pyramid scheme .
The two scheme is based on paying the earlier backers by the new investors .
Hence , from the question information , the given example is of a a Ponzi scheme .