Ijust need figuring out how to set it up.

You don't have to set it up.  It's already set up.  You only have to identify the correct set-up from the four choices.

The correct one is 'B', and it's a formula that you really should memorize.
You'll be using it in any science class that you take.

 Weight of an object = (the object's mass) x (the local acceleration of gravity) .

                             W  =  m  x  g

The object's mass never changes.  But its weight does, whenever
it goes to places where the acceleration of gravity is different.
That's why the same astronaut has different weights on Earth
and on the moon.


Also, by the way, that bit about the "pendulum bob" in this question
may be there mainly to distract and confuse you.  Everything I said
up there above the line is true for ANY object ... a pendulum bob,
a gold fish, a newborn baby, a turtle, a tree, a school-bus, a rock,
a house, a jug of milk, a book, a computer, a burrito, a puppy,
a snowball, an airplane, a cigar, or anything else.

             Weight anyplace  =  (mass) x (gravity in that place)

B) raising the temperature and reducing the volume of the gas.|-/ 

Awoodchuck would chuck all the wood he could chuck if a woodchuck could chuck wood.