The normal physiologic change of aging that places an elderly client at an increased risk for digitalis toxicity is decreased:
a. gastrointestinal motility
b. bone density
c. vital capacity
d. glomerular filtration

The correct answer is option d, that is, glomerular filtration.

Explanation:

Digitalis toxicity can take place when one consumes too much digoxin or digitalis. It is a medicine, which is used in the treatment of heart conditions. The symptoms of toxicity comprise vomiting, nausea, and an unusual heartbeat.  

In older individuals, the defect in the functions of the kidney may enhance the occurrence of digitalis toxicity. In the patients suffering from diminished glomerular filtration, the half-life of digitalis can get extended. This may eventually lead to an enhanced concentration of digitalis in the blood or known as digitalis toxicity.  

not sure if this what   you'r looking for would be percent composition