Constant = straight line
“Travels at constant negative acc.”
Which is negative slope
Solution: B. Straight line w/ neg. slope
Weight of the carriage 
Normal force 
Frictional force 
Acceleration 
Explanation:
We have to look into the FBD of the carriage.
Horizontal forces and Vertical forces separately.
To calculate Weight we know that both the mass of the baby and the carriage will be added.
- So Weight(W)

To calculate normal force we have to look upon the vertical component of forces, as Normal force is acting vertically.We have weight which is a downward force along with
, force of
acting vertically downward.Both are downward and Normal is upward so Normal force 
- Normal force (N)

- Frictional force (f)

To calculate acceleration we will use Newtons second law.
That is Force is product of mass and acceleration.
We can see in the diagram that
and
component of forces.
So Fnet = Fy(Horizontal) - f(friction) 
- Acceleration (a) =

So we have the weight of the carriage, normal force,frictional force and acceleration.
I was about to say: because people generally get comfortable with
what they think they know, and don't like the discomfort of being told
that they have to change something they're comfortable with.
But then I thought about it a little bit more, and I have a different answer.
"Society" might initially reject a new scientific theory, because 'society'
is totally unequipped to render judgement of any kind regarding any
development in Science.
First of all, 'Society' is a thing that's made of a bunch of people, so it's
inherently unequipped to deal with scientific news. Anything that 'Society'
decides has a lot of the mob psychology in it, and a public opinion poll or
a popularity contest are terrible ways to evaluate a scientific discovery.
Second, let's face it. The main ingredient that comprises 'Society' ... people ...
are generally uneducated, unknowledgeable, unqualified, and clueless in the
substance, the history, and the methods of scientific inquiry and reporting.
There may be very good reasons that some particular a new scientific theory
should be rejected, or at least seriously questioned. But believe me, 'Society'
doesn't have them.
That's pretty much why.
Voltage - V = IR : v= voltage i= current r= resistance
because as the distance increases the gravitational force decreases so the weight of a body decreases