Question

in this investment, the brokers promise incredibly good and/or incredibly reliable returns. the return is great – for a while. but the money is not being invested in anything. instead, the new money from investors is used to pay the obligations to the old investors, including the exaggerated returns promised to those who \got in on the ground floor.\ however, the “investment” cannot bring in enough new money to sustain itself and entire investment collapses.

○ pump and dump
○ pyramid
○ bait and switch
○ ponzi scheme

Explanation:

A Ponzi scheme uses new investors' money to pay old investors' returns, with no real investment. The description matches this: new money pays old obligations, collapses when new money dries up. "Pump and dump" manipulates stock prices, "pyramid" relies on recruiting, "bait and switch" is a sales tactic—none fit as well as Ponzi scheme.

Answer:

D. ponzi scheme