Question

which substance has the highest variability?
uric acid
phosphate
oxalate

Explanation:

Step1: Understand variability in bar - chart

Variability is represented by the length of the error bars. Longer error bars mean higher variability.

Step2: Compare error - bar lengths

Looking at the error bars for phosphate, oxalate, and uric acid. The error bar for uric acid is the longest.

Answer:

uric acid