Principles of enzyme purification and specific activity:

• Statement (I) is correct: Specific activity is rigorously defined as the ratio of total enzyme activity (units, $\mu\text{mol/min}$) to total protein mass (mg), expressed as $\text{Units/mg of protein}$.
• Statement (II) is correct: During a purification protocol, contaminating non-target proteins are selectively removed, causing specific activity to increase steadily; when the enzyme is completely purified to homogeneity, specific activity reaches a constant theoretical maximum that does not increase upon further chromatographic steps.

Stereochemistry and mutarotation of glucose anomers:

• Assertion (A) is true: Pure crystalline $\alpha$-D-glucopyranose has an initial specific rotation of $+112.2^\circ$, while pure $\beta$-D-glucopyranose has an initial rotation of $+18.7^\circ$. When either anomer is dissolved in water, mutarotation spontaneously occurs via reversible open-chain ring opening until both solutions settle at an identical final optical rotation of $+52.7^\circ$.
• Reason (R) is true: The spontaneous mutarotation process converges on an identical thermodynamic equilibrium mixture containing approximately $64\%\;\beta$-anomer, $36\%\;\alpha$-anomer, and $\lt 0.02\%$ open-chain form.
• Because both solutions converge on the exact same molecular composition at equilibrium, their macroscopic optical rotation properties become completely identical, meaning Reason (R) is the direct explanation of Assertion (A).