Answer:
D) we would still orbit it in a period of one year
Step-by-step explanation:
Since, the mass of the Sun and the black hole is same, the gravitational pull experienced by the Planet Earth will be same, the gravitational pull is dependent only upon the masses of the system and the distance between them, which is same in the given case. Therefore, Earth would still orbit it in a period of one year.
Hence option D is correct.