Which statement best describes a reference angle in trigonometry?

A reference angle is defined as the smallest angle formed between the terminal side of an angle and the x-axis. It simplifies the process of solving trigonometric problems because it helps to find the sine, cosine, and tangent values of angles that are greater than 90 degrees or less than zero. By identifying the reference angle, one can relate any angle to its corresponding acute angle, which makes calculations and concepts easier to manage.

In specific terms, if you have an angle in standard position, the reference angle is always taken to be the acute angle formed with the x-axis, which is a key reason why option B is the best description. It reflects the fundamental purpose of a reference angle in facilitating easier trigonometric calculations and understanding the values of trigonometric functions.