**Core Concept**
The patient's situation illustrates the phenomenon of nitrate tolerance, a common complication of long-term nitrate therapy. Nitrate tolerance occurs when the body adapts to the constant presence of nitrates, leading to a decrease in their therapeutic efficacy.

**Why the Correct Answer is Right**
Nitrate tolerance is thought to be mediated by the development of endothelial dysfunction, which leads to a decrease in the production of nitric oxide (NO). Normally, NO causes the smooth muscle of blood vessels to relax, leading to vasodilation and a decrease in blood pressure. In the presence of nitrates, the body adapts by downregulating the production of NO, reducing the effectiveness of the nitrates. This is because the body "learns" to rely on the nitrates to produce the vasodilatory effect, rather than producing NO itself. As a result, the patient experiences an increase in anginal attacks, despite continued use of the nitroglycerin patches.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not applicable to the scenario described, as it does not relate to the development of nitrate tolerance.
**Option B:** This option is incorrect because it does not address the underlying mechanism of nitrate tolerance. While it is true that nitrates can cause a decrease in blood pressure, this is not the primary reason for the development of tolerance.
**Option C:** This option is incorrect because it is a potential consequence of nitrate therapy, but not the primary reason for the development of tolerance.

**Clinical Pearl / High-Yield Fact**
A common strategy to prevent nitrate tolerance is to use a "nitrate-free" interval of at least 8-12 hours between patch changes. This allows the body to "reset" its production of NO, reducing the likelihood of tolerance development.

**Correct Answer:**
C.