Banks primarily generate profit (and maximize net interest margin) by engaging in maturity and liquidity transformation, which typically involves taking short-term, liquid liabilities (like deposits) and turning them into long-term, illiquid assets (like loans). While this strategy maximizes net interest margins, it exposes banks to liquidity risk. To mitigate this risk without completely matching maturities, banks maintain ample buffers of cash and highly liquid assets.

Statement A is incorrect because retail deposits, not short-term wholesale funding, are typically the most reliable source of borrowing. Statement B is incorrect because perfectly matching maturities would eliminate maturity transformation, thereby minimizing (not maximizing) net interest margins. Statement D is incorrect because ALM strategies cannot "fully insulate" a bank against severe systemic runs or sudden stops in short-term funding.