Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follow(s) from the statements.
Statements:
All meteors are asteroids.
All planets are asteroids.
Conclusions:
I. Some planets are meteors.
II. No planet is a meteor.

Let's take a look at the conclusions:

(1) Some planets are meteors
This might or might not be true depending on whether the overlapping area of meteors and planets is empty. 

(2) No planet is a meteor
This, too, might or might not be true depending on whether the metros' overlapping areas have at least one element. 

Looking at the statements together, if the overlapping area is empty, then conclusion 2 is true, and if it is not empty then conclusions 1 is true. 

So, only one of the conclusions 1 and 2 can be true. 

Therefore, option A is the correct answer.