Final answer:
The asteroid will take 10^7 days to reach Earth.
Step-by-step explanation:
To determine how many days it will take for the asteroid to reach Earth, we need to divide the distance between the asteroid and Earth by the speed at which it is traveling.
Given that the asteroid is 10^12 miles away from Earth and traveling at a speed of 10^5 miles per day, the number of days it will take for the asteroid to reach Earth can be calculated as:
10^12 miles / 10^5 miles per day = 10^(12-5) days = 10^7 days
Therefore, the correct answer is A) 10^7 days.