Final answer:
The therapeutic response to calcium citrate in a hypocalcemic client would be indicated by improved respiratory function due to the essential role of calcium in muscle contraction.
Step-by-step explanation:
A client with hypocalcemia who is receiving calcium citrate is expected to have an increase in serum calcium levels as a therapeutic response. Therefore, out of the options provided, "Decreased serum calcium levels" would not indicate a therapeutic response to the medication. Instead, improved body functions resulting from corrected calcium levels is the desired outcome. Specifically, improved respiratory function could be a sign of successful treatment since adequate serum calcium is necessary for muscle contraction, which is integral for respiration. The therapeutic response to calcium citrate in a hypocalcemic client would be indicated by improved respiratory function due to the essential role of calcium in muscle contraction.