Final answer:
The most crucial step in securing a patent is filing a patent application with the appropriate authorities, which provides the inventor with exclusive rights for a typically 20-year period.
Step-by-step explanation:
The key step for securing a patent during the invention process is most likely c) Filing a patent application with the appropriate authorities. Development of a prototype, conducting a literature review, and collaborating with experts are all essential parts of the invention process, but it is the formal submission of a patent application that starts the legal process of securing a patent. Patents are a form of intellectual property rights that provide the inventor exclusive rights to their invention for a limited time, typically 20 years. By obtaining a patent, an inventor can protect their invention from being made, used, or sold by others without permission.