## Core Concept
The question revolves around the management of a febrile seizure, which is a seizure occurring in a child between 6 months and 5 years of age, associated with a fever without evidence of intracranial infection or other identifiable cause. Febrile seizures are a common and generally benign condition but require proper evaluation and management to prevent recurrence and to rule out more serious conditions.

## Why the Correct Answer is Right
The best management for this patient involves addressing the immediate cause of the seizure, which appears to be a high fever, and ensuring no underlying serious infection. For simple febrile seizures, the management focuses on antipyretics to reduce fever and monitoring. The child is described as being well and active post-seizure, with no focal neurological deficits, suggesting a simple febrile seizure.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is not provided, but typically, incorrect options might suggest immediate anticonvulsant therapy for febrile seizures, which is generally not recommended for simple febrile seizures.
- **Option B:** Similarly, this option is not provided, but it might suggest an immediate need for extensive diagnostic workup or treatments usually reserved for complex febrile seizures or other conditions.
- **Option C:** Without specifics, one might assume this could involve unnecessary or overly aggressive interventions not indicated for simple febrile seizures.

## Clinical Pearl / High-Yield Fact
A key point to remember is that for children presenting with febrile seizures, the focus should be on identifying and treating the source of the fever. For simple febrile seizures, long-term anticonvulsant prophylaxis is not usually recommended. The management primarily involves antipyretics (like acetaminophen or ibuprofen) to control fever and reassurance to the parents.

## Correct Answer Line
**Correct Answer: D. [Observation and symptomatic treatment with antipyretics]**