Final answer:
A provisional patent application can be used to establish the date of conception of an invention. Correct option is 1)
Step-by-step explanation:
A provisional patent application can be used to establish the date of conception of an invention. This is true.
A provisional patent application is a temporary application that allows inventors to establish an early priority date for their invention. It provides the inventor with a one-year period during which they can further develop and refine their invention before filing a regular patent application.
By filing a provisional patent application, the inventor can ensure that they have proof of the date of conception of their invention, which can be important in establishing priority of invention in case of any patent disputes or challenges in the future.