Ethnographers Sometimes Write Down Key Words or Quotations While They're

Ethnographers sometimes write down key words or quotations while they're interacting with people. Given that they will write much more detailed fieldnotes later, what is the advantage of these brief, sketchy notes?

A) They are not as difficult to compile as comprehensive fieldnotes.
B) They are more ethical.
C) They are an aid to memory when writing more detailed fieldnotes.
D) They involve reflexivity.
E) They allow the ethnographer to achieve thick description.