**Core Concept**
Lidocaine is a local anesthetic and antiarrhythmic medication that belongs to the amide class. It works by inhibiting the sodium channels in nerve fibers, preventing the initiation and transmission of nerve impulses.

**Why the Correct Answer is Right**
Lidocaine is classified as an amide-type local anesthetic, not an ester-type. This distinction is crucial because amide-type anesthetics are metabolized by the liver, whereas ester-type anesthetics are metabolized by plasma cholinesterase. The amide structure of lidocaine allows it to have a longer duration of action and reduced toxicity compared to ester-type anesthetics.

**Why Each Wrong Option is Incorrect**
**Option A:** The local anesthetic effect (LA effect) of lidocaine is indeed true, as it blocks nerve impulses to provide local anesthesia.
**Option B:** Lidocaine is also used to treat cardiac arrhythmias, making this statement true.
**Option D:** Lidocaine can act on mucous membranes, but this is not the most relevant or specific characteristic of the drug.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that amide-type local anesthetics like lidocaine are generally preferred over ester-type anesthetics due to their longer duration of action and reduced toxicity.

**✓ Correct Answer: C. Ester**