For an ideal gas confined to a rigid container, which of the following best describes the relationship between pressure P and absolute temperature T when the amount of gas remains fixed?
a) P increases with the square root of T, following a square–root curve
b) P varies linearly with T and the line passes through the origin
c) P decreases inversely with T following a hyperbolic curve
d) P varies linearly with T but the line intersects the T-axis at a positive value of T