Step-by-step explanation:
Orbital radius,
![r=1\ AU=1.496* 10^(11)\ m](https://img.qammunity.org/2020/formulas/physics/college/7hswvfy2judv9f0cgus4fj7wp9v18d33sd.png)
According to Kepler's law :
![T^2\propto r^3](https://img.qammunity.org/2020/formulas/physics/college/hij6ew9i13g0g4m5v5qujpj9rcjjd771s6.png)
Where
M is the mass of sun,
![M=1.98* 10^(30)\ kg](https://img.qammunity.org/2020/formulas/physics/college/il2yih6ng4iqmtqcm1h5oej4yntadwwyu9.png)
![T^2=(4\pi^2* (1.496* 10^(11))^3)/(6.67* 10^(-11)* 1.98* 10^(30))](https://img.qammunity.org/2020/formulas/physics/college/yiy7lpgtj9rh9asg4btgk0q6j46en6lcfs.png)
![T=\sqrt{1.0008* 10^(15)}](https://img.qammunity.org/2020/formulas/physics/college/zfn9wyxtnvnyjrt8bd6q7t2ylrfowydq6z.png)
T = 31635423.18 s
or
T = 1.0003 years
So, a solar-system planet that has an orbital radius of 1 AU would have an orbital period of about 1.0003 year(s).