Review the content.

"offers very basic information on an upcoming event."

Which identifies the type of informational text that includes this content

A: poster

B: manual

C: newsletter

D: Menu

I would choose A. Here is why!

A poster dedicated to something would most likely not be too detailed

A Manuel would be very detailed, so B is out

A newsletter would be very detailed on the information it gives. C is out

A menu is very detailed. Usually due to food allergies. D is out

A is the only opinion left!