**Core Concept**
The patient's presentation of hypotension and bradycardia is a classic case of hyperkalemia, a condition characterized by elevated potassium levels in the blood. This occurs due to the inhibition of the renin-angiotensin-aldosterone system (RAAS) by the combination of losartan (an angiotensin II receptor antagonist) and spironolactone (a potassium-sparing diuretic).

**Why the Correct Answer is Right**
The RAAS plays a crucial role in regulating blood pressure and electrolyte balance. Angiotensin II stimulates the release of aldosterone, which promotes sodium retention and potassium excretion in the kidneys. Spironolactone blocks the effects of aldosterone, leading to increased potassium levels. Losartan blocks the action of angiotensin II, further disrupting the RAAS and contributing to hyperkalemia. In this scenario, the patient's ECG likely shows peaked T waves, a classic sign of hyperkalemia. To manage this condition, it is essential to counteract the effects of the RAAS inhibitors and reduce potassium levels.

**Why Each Wrong Option is Incorrect**
**Option A:** Administering a beta-blocker would worsen the patient's bradycardia, making this option incorrect.
**Option B:** Increasing the dose of losartan or spironolactone would further disrupt the RAAS and exacerbate hyperkalemia, making this option incorrect.

**Clinical Pearl / High-Yield Fact**
In patients taking RAAS inhibitors, it is crucial to monitor potassium levels closely and adjust therapy accordingly. A combination of losartan and spironolactone increases the risk of hyperkalemia, and healthcare providers should be aware of this potential interaction.

**Correct Answer: C. Calcium gluconate, insulin, and glucose should be administered to counteract the effects of hyperkalemia.**