Which of these are not forms of flash fiction?
[A] Drabble
[B] Postcard fiction
[C] Novelette
[D] Short story
[E] Nanofiction
Choose the most appropriate answer from the options given below:

The correct option is A and E only.

To understand this classification, we can examine the structural definitions of the given literary terms:
1. Drabble [A]: A drabble is a highly specific, extreme form of writing where the story must be exactly 100 words long. Because of this rigid constraint, it is frequently categorized under microfiction rather than standard flash fiction.
2. Postcard fiction [B]: This is a classic form of flash fiction designed to be short enough to fit on the back of a postcard, typically spanning 250 to 500 words.
3. Novelette [C]: A novelette is a longer prose narrative, typically containing between 7,500 and 17,500 words.
4. Short story [D]: A standard short story is a fully developed narrative that is typically between 1,000 and 7,500 words.
5. Nanofiction [E]: Nanofiction refers to stories of extreme brevity, usually containing fewer than 55 words, placing it in a distinct category of micro-narrative separate from standard flash fiction.

Consequently, Drabble (A) and Nanofiction (E) are distinguished as not being standard forms of flash fiction, confirming A and E only as the correct option.