The first word names a bodily state and the second names the fluid the body releases because of it. Sorrow makes a person shed tears, so fatigue, meaning tiredness from exertion, makes the body release perspiration, that is sweat.
Fatigue leads to perspiration just as sorrow leads to tears, so the answer is perspiration.
If the price of a commodity increases by 25%, by what percentage should the consumption be reduced to keep the expenditure the same?