Final answer:
The correct answer is option C. John, who is an investment banker with financial training, should be receptive to speculative investments with higher risks.
Step-by-step explanation:
The individual who should be receptive to speculative investments with higher risks is C. John, who is an investment banker with financial training.
As an investment banker, John likely has a deeper understanding of financial markets and investment strategies compared to the other individuals. His financial training and expertise could provide him with the knowledge and skills necessary to assess and manage the risks associated with speculative investments. Additionally, as a professional in the finance industry, John may have a higher tolerance for risk and be willing to take on higher risk investments in order to potentially achieve higher returns.