If pressure of the liquid is decreased,the boiling point will:?

Question

increase,decrease,remain the same.

Answer 1

First of all, you don't have a "pressure of the liquid".  Gases have pressures.  What you mean to say, I think, is, "If the pressure of the vapors of the liquid are decreased..."

Boiling occurs at the temperature where the vapor pressure of a liquid equals the ambient pressure.  The only way to control the vapor pressure of a liquid is by changing its temperature.  The higher the temperature, the greater will be the vapor pressure.

Your question still needs some work because what will actually affect the boiling point will be the ambient or atmospheric pressure.  So your question should read, "If the atmospheric pressure is decreased, the boiling point will do what?

And the answer to that question is "decrease".  When the ambient pressure is decreased, then the liquid can boil at a lower temperature where the vapor pressure is equal to the lowered atmospheric pressure.

Answer 2

Decrease.

Answer 3

increase