**Core Concept**
Absence seizures, previously known as petit mal seizures, are a type of generalized seizure disorder characterized by brief, sudden lapses in consciousness. The electroencephalogram (EEG) plays a crucial role in diagnosing absence seizures by detecting specific patterns of abnormal brain activity.

**Why the Correct Answer is Right**
The characteristic EEG feature of absence seizures is a generalized 3 Hz spike-and-wave discharge. This pattern is typically seen in both hemispheres of the brain and is synchronous across all leads. The 3 Hz frequency is a key distinguishing feature of absence seizures from other types of seizures. The spike-and-wave discharge is thought to result from abnormal synchronization of neuronal activity in the thalamocortical circuits.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not describe a specific EEG pattern associated with absence seizures. While generalized seizures may exhibit a variety of EEG abnormalities, a 3 Hz spike-and-wave discharge is the hallmark of absence seizures.

**Option B:** This option is incorrect because it describes a pattern more commonly associated with focal seizures, such as a focal sharp wave or a focal slow wave. These patterns are typically seen in one hemisphere of the brain and are not characteristic of absence seizures.

**Option C:** This option is incorrect because it describes a pattern more commonly associated with status epilepticus, such as a continuous spike-and-wave discharge or a periodic lateralized epileptiform discharge. These patterns are typically seen in the setting of prolonged seizure activity and are not characteristic of absence seizures.

**Option D:** This option is incorrect because it does not describe a specific EEG pattern associated with absence seizures. While generalized seizures may exhibit a variety of EEG abnormalities, a 3 Hz spike-and-wave discharge is the hallmark of absence seizures.

**Clinical Pearl / High-Yield Fact**
It's essential to note that the 3 Hz spike-and-wave discharge in absence seizures can be subtle and may require careful inspection of the EEG to detect. Additionally, absence seizures can be difficult to diagnose clinically, as they often present with brief, sudden lapses in consciousness without warning signs.

**Correct Answer:** C.