Answer:
A. % recovery
Explanation:
Percentage yield or percentage value is defined as the mass/amount of a substance/compound obtained from a chemical reaction(e.g purification, crystallization) to the theoretical mass/amount of the substance expected. It finds use in the determination of the efficiency of the chemical reaction process.
Percentage recovery is by definition the mass/amount of a pure substance to the mass/amount of the impure substance. It finds use in recrystallisation processes.
Differences in percentage yield and percentage recovery is that in percentage yield, ratio between actual yield and theoretical yield is calculated while percentage recovery is the ratio of the pure substance and initial substance.