At what concentration does gasoline become flammable?

Gasoline becomes flammable at a concentration that typically ranges between 1.4% and 7.6% in air, which translates to approximately 14,000 to 76,000 ppm. Thus, the correct choice pertains to gasoline concentrations that can cause flammability.

1.4 x 10^6 ppm would equate to 1,400,000 ppm, which is significantly higher than the flammability range for gasoline. While it is a high concentration, it exceeds practical levels where gasoline would normally ignite in typical atmospheric conditions.

In the context of the choices, the correct concentration that indicates gasoline becoming flammable should actually fall within the lower ranges closer to the concentrations given in other options rather than the astronomical figures provided in this particular choice. However, it is essential to note that the idea of flammability depends on achieving a specific vapor concentration in the air, and the concentration of 14 x 10^6 ppm is unrealistically high and would not be relevant in typical scenarios.

Understanding the actual flammable limits helps in safety measures and hazardous material handling, ensuring that individuals are aware of the thresholds that can lead to dangerous situations involving gasoline.