All of the matter in the universe formed after the big bang. Scientists predicted that hydrogen and helium would be the most abundant elements.
What did scientists discover?
A. The universe has 74% hydrogen and 24% helium, which supports
the big bang theory.
B. Stars are made mostly of other elements, which supports the big
bang theory
C. The universe has 73% hydrogen and 25% helium, which does not
support the big bang theory.
D. Planets are made mostly of other elements, which does not
support the big bang theory.

The answer is A. Here is proof

Explanation:

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.