Correct
笔谈
/ bǐtán /
Strokes
Definition
to communicate by means of written notes (instead of speaking)/to publish one's opinion (e.g. as part of a scholarly dialogue)/(in book titles) essays/sketches
Example
As a Verb
exchange ideas by way of writing instead of conversation
As a Verb
comment in writing
As a Noun
［often used in book titles］ sketches; notes