In the context of Secular Meditation, Herbert Benson states that a simple way to attain a state of relaxation is to _____.
A. Concentrate on a single object with each rhythmic breath out
B. Repeat the word "one" in one's mind with each rhythmic breath out
C. Shift focus from a tangible object to an intangible object with each rhythmic breath out
D. Concentrate on different intangible objects with each rhythmic breath out