C” has remained the same for over fifty years
<span>Freestyle motocross is an auto-sport as it is a type of motorcycle racing. It's one of two types of motocross which involves tracks of multiple hills that involves competitors making jumps of varying lengths. These routines, performances, can last from a little over a minute to a quarter hour.</span>
Answer: The results may be due to a CEILING EFFECT effect.
Explanation: The ceiling effect is defined as a phenomenon whereby an independent variable (noise level) no longer has an effect on a dependent variable (reading comprehension).