Stoichiometry and energetic balance of homolactic lactose fermentation:

• One molecule of lactose ($C_{12}H_{22}O_{11}$) is hydrolyzed into its two constituent hexose monomers: D-glucose and D-galactose.
• In homofermentative lactic acid bacteria (e.g., Lactococcus lactis via the tagatose-6-phosphate or Leloir pathway), both glucose and galactose enter glycolysis (Embden-Meyerhof-Parnas pathway).
• Each hexose yields 2 molecules of pyruvate, which are reduced by lactate dehydrogenase to 2 molecules of lactic acid, generating a net total of $4\text{ moles of Lactic Acid}$ per mole of lactose.
• Glycolytic substrate-level phosphorylation yields a net of 2 ATP per hexose, producing a net total of $4\text{ ATP}$ from $4\text{ ADP} + 4\text{ H}_3\text{PO}_4$, with 3 moles of water generated in the overall balanced equation:
  $$\text{Lactose} + 4\text{ ADP} + 4\text{ H}_3\text{PO}_4 \rightarrow 4\text{ Lactic Acid} + 4\text{ ATP} + 3\text{ H}_2\text{O}$$

Enzyme renaturation and false-positive pasteurization diagnostics:
(A), (B), (C) do not exhibit significant reversible renaturation producing diagnostic false-positives.
(D) Alkaline phosphatase (ALP) is the statutory index enzyme for verifying proper milk pasteurization. However, when milk (particularly high-fat cream or milk subjected to ultra-pasteurization / HTST treatments $\gt 72^\circ\text{C}$ for short holding times) is held at room temperature ($20\text{--}30^\circ\text{C}$) in the presence of magnesium and zinc ions, denatured monomer subunits can reassemble and spontaneously regain catalytic activity. This phenomenon, known as 'enzyme reactivation', generates a false-positive result in the Aschaffenburg-Mullen or fluorometric ALP test, falsely suggesting under-pasteurization.

Oxidation-reduction dynamics in dairy fermentations:

• Assertion (A) is true: Fresh raw or pasteurized milk saturated with air possesses a positive oxidation-reduction potential ($E_h \approx +200\text{ to }+300\text{ mV}$). In stark contrast, Cheddar and other ripened cheeses maintain an intensely reducing, strongly negative redox potential ($E_h \approx -100\text{ to }-250\text{ mV}$).
• Reason (R) is true and provides the exact explanation: As lactic starter bacteria multiply during cheese manufacturing and curd acidification, they rapidly respire and consume dissolved oxygen. Once oxygen is depleted, active metabolic generation of reducing sulfur groups ($-SH$ from cysteine) and reducing intermediates causes an abrupt drop in $E_h$ into the negative territory, establishing an anaerobic reducing environment essential for flavor compound stability and preventing aerobic spoilage.