From the periodic table:
molar mass of carbon = 12 gm
molar mass of hydrogen = 1 gm
molar mass of oxygen = 16 gm
molar mass of <span>acetylsalicylic acid = 9(12) + 8(1) + 4(16) = 180 gm
Number of moles = mass / molar mass = 0.5 / 180 = 2.778 x 10^-3 moles
To get the number of molecules, we multiply the number of moles by Avogadro's number as follows:
number of molecules = </span>2.778x10^-3x6.02x10^23 =1.672 x 10^21 molecules
For this question, lets apply Avagadro's law
when Pressure and temperature are constant, the volume occupied is directly proportional to the number of moles of gases.

where V-volume, n-number of moles and k - constant
Therefore at 2 instances

where V1 and n1 are for 1st instance
and V2 and n2 are for 2nd instance
therefore

V1 = 2.4 L
n1 = 3.7 mol
n2 = 3.7 + 1.6 = 5.3 mol
since more He moles are added at the 2nd instance its the sum of the moles.
V2 needs to be calculated

V2 = 2.4 x 5.3 / 3.7
= 3.4 L
Answer is 1st option 3.4 L
Answer : The correct answer is option C.
Explanation:
Astronomers have observed that light from the distant object in the universe is shifted towards the frequency of red color which indicates that those object are receding or moving away from the planet earth.This phenomena was termed as Red shift .Same thing goes for galaxies which are very far away from the planet earth.
Where as if galaxies were moving towards the the planet earth their light would have shifted toward the frequency of blue color termed as blue shift.
Hence, the correct answer is option C.