Hey there!:
Here the Statement - D is correct.
Because Orbitals containing the core electrons are more attracted towards nuclear charge and hence less shilded from nuclear charge than an orbital that doesn't penetrate. Also due to more attraction between the orbital containing core electron and nucleus, it will have less energy.
Hope this helps!
The work done to pull the sled up to the hill is given by

where
F is the intensity of the force
d is the distance where the force is applied.
In our problem, the work done is

and the distance through which the force is applied is

, so we can calculate the average force by re-arranging the previous equation and by using these data:
I think the answer is 30 but I’m not sure
A. dependent variable
As the the independent variable (i.e. number of cats being sold) increases, the dependent variable (i.e. money made) will also increase. You can have 1,000,000 cats for sale and make no money, but you cannot make money without having sold some cats first.
Hope my weird example helped!