It is much easier to slice a piece of pie with the edge of a sharp knife than with the edge of a pencil. Explain this in terms of applied pressure. Just Putting this out there for other students

The Knife will have more pressure than the edge of a pencil because it has less area. The pencil will have less pressure than the knife because it has more area.

Note: As pressure increases the area will decrease and as the area increases the pressure will decrease.

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.

the answer is b   just took the test