Final answer:
Liquid A, with a lower boiling point of 145ºC, will have a higher vapor pressure at 80ºC compared to liquid B, which boils at 190ºC.
Step-by-step explanation:
Among liquids A and B, which boil at 145ºC and 190ºC respectively, liquid A will have the higher vapor pressure at 80ºC. This conclusion is reached because vapor pressure increases with temperature, but isn't directly proportional to the boiling point. Liquids that boil at lower temperatures typically have higher vapor pressures at a given temperature below their boiling points because they can more readily turn into vapor at lower temperatures. Hence, liquid A, which boils at the lower temperature of 145ºC compared to liquid B's 190ºC, will have a higher vapor pressure at 80ºC.