In which of these samples do the molecules most likely have the least kinetic energy? (1 point)   molten iron at 1600°c solid iron at 25°c solid iron at 98°c iron vapor at 2900°c

The answer is solid iron at 25C
Temperature is a measure of the average random kinetic energy of the particles in a substance - in other words, the higher the temperature, the higher the average random Kinetic Energy is. Hence, in the Kelvin Scale, absolute zero means the particles have no energy at all which (as of present) is impossible to achieve.

In this problem it decreased 20%