Final answer:
Jonas could benefit from learning to adapt and be more flexible, as this would allow him to handle life's uncertainties more effectively and reduce his frustration when things don't go as planned.
Step-by-step explanation:
Jonas prides himself on living spontaneously, but he faces frustration when things do not align with his expectations. An idea that might help him is C) Learning to adapt and be more flexible. By embracing flexibility and psychological preparedness, Jonas can develop the resilience to navigate life's unpredictability and reduce frustration. Practices such as living with less and embracing nature during a backpacking trip can lead to greater adaptability and an understanding that discomfort can be managed and even transformed into a confidence-building experience. By maintaining a flexible approach to life's vicissitudes, Jonas can also stay open to new possibilities and adapt his goals as he gains experience and knowledge, creating a life that continues to evolve constructively in the face of uncertainty.