They are part of an organ system
The answer is B. Spine stretch
Spine stretch is an exercise to stretch your back bone, which mean your upper body, not the lower one.
NB :
Hip Flexor : To stretch your thigh
Calf stretch & Harmstring stretch : To stretch your lower legs
I would have to say the answer is C.
A is incorrect since hydrogen is not an air pollutant.
B is incorrect because ozone is most definitely one of the top.
And D has cyanide which is a chemical for suicide during wars.
Hope this helps!
In it they stated that the United States Constitution would grant a competent person a constitutionally protected right to refuse<span> life-saving </span>medical treatment<span> Whether for financial, spiritual or religious reasons, a </span>patient has<span> the ultimate say over what is done to his or her body.</span>
