Answer: first option V₁/T₁ = V₂/T₂
Step-by-step explanation:
1) The ideal gas equation is PV = nRT.
2) R is the Universal Constant of gases, so ... it is constant.
3) When the amount of gas is the same (n is constant) and the pressure does not change (P is constant), the equation becomes:
V / T = nR/P = constant.
That means that V₁ / T₁ = V₂ / T₂ = V₃ / T₃ ....
So, the option 1 has been proved.
Note that that is Charles' law.