Determining a person's reaction time (in milliseconds) would involve measurement on a(n) scale of measurement.

Correct Ratio

Determining a person’s reaction time would involve measurement on a ratio scale that is expressed in milliseconds. It is a point where none of the quality being measured exists and its scale has an absolute zero. In ratio scale, it allows comparisons such as being twice as high or one-half as much. Additionally, in the case of a person’s reaction time, it can be state that a response of 25 milliseconds is twice as fast as a response time of 50 milliseconds.

the supermassive black hole is in the middle of the galaxy.

b.have there own function.