In outer space, distances between object such as galaxies can be so vast that a new unit is used to measure them. This unit uses the distance cover by the fastest moving thing in the universe in a year. This is called a(n) A) lightyear. B) atomic year. C) galactic unit. D) astronomical unit.

Option D is correct.

Explanation:

The distance between the galaxies is measured in astronomical unit. Our solar system is very large so for the measurement the distance between two objects we use the greatest unit of measurement which is astronomical unit.

In short it is represented as AU.

1 AU =  1.49× = 149 million kilometers

The distance between the sun & earth is around  149 million kilometers. in other words we can say The distance between the sun & earth is 1 AU.

Therefore option D is correct.

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min