Concept:
Acute stress disorder occurs after exposure to a traumatic event and presents with symptoms such as flashbacks, anxiety, emotional disturbance, and dissociative symptoms. The duration is from 3 days to 1 month after trauma.
Step 1: Identify the traumatic event.
The patient developed symptoms after her father's death in a road traffic accident. This is a significant traumatic event.
Step 2: Identify the symptoms.
She has:
\[
\text{Amnesia + flashbacks}
\]
These are trauma-related symptoms.
Step 3: Use the duration to differentiate.
The symptoms have persisted for:
\[
2 \text{ weeks}
\]
Since the duration is less than 1 month, the diagnosis is acute stress disorder, not PTSD.
Therefore, the correct answer is Acute stress disorder.