Answer:
answer D. all of the above
The correct answer is - Positive acceleration describes an increase in speed; negative acceleration describes a decrease in speed.
We have that F=ma from the 2nd Newton law where F is the force, m is the mass and a is the acceleration. Suppose we have that F' is the new force and m' is the new mass. Then, we have that a'=F'/m' still, by rearranging Newton's law. We are given that F'=2F and m'=m/2. Hence,

But now, we have from F=ma, that a=F/m and we are given that a=1m/s^2.
We can substitute thus, a'=4a=4*1m/s^2=4m/s^2.
Answer:
I have no clue what's really going on I'm just here to get answer maybe I will just try to get an answer but I have no clue I'm sorry I am confused and dint really know what to do here.
Carbon tetrahydride is B. CH4