Is this answer is correct (science 6th grade)?

Question

I had to take these sixth grade CBE (Credit By Exam) which isn't my grade I just got out of 7th anyways are theses answers correct?

Here are the Questions I don't remember the exactly but it was asking the same thing:

If you push on a stationary wall with the force of 20N. What force does it exert on you?

a. 20N forward

b. 20 N backward

c. 10 N forward

d. 10N backward

I marked D

What causes a weathered rock to get its reddish color?

a. oxidation

b. ironation

c. carbon-dioxide

d. I forgot what this one was sorry

But I marked C

Now the last one How can you tell if a mountain is done forming? (not multiple choice)

I wrote: You have to be able to tell if the plates are still moving.

Answer 1

Refer the Newtobns law. Every action has got equal and opposite reaction.Therefore as per his proved law it is b.The next is a.But honestly saying I am not sure.

Answer 2

B

A

The mountain will start getting smaller indtead of larger