According to Boyle’s law, For a fixed amount of an ideal gas kept at a fixed temperature, P (pressure) and V (volume) are inversely proportional.
Therefore,

Given
,
and
.
Thus,

Answer:
option D
Explanation:
given,

increase the intensity by factor of 9
I₁ = I₀
I₂ = 9 I₀
now,




A₂ = 3 A₁
hence, amplitude increase with the factor of 3
so, the correct answer is option D