15. In the lab beneath Tall Oaks, Ada finds an item labelled 'Happy Birthday Ada Wong'. What exactly does she find?
From Quiz "Resident Evil 6" - Ada's Story
Answer:
Videotape
The battle between Ada, Leon, and Helena against Deborah will take the trio deep into the mines, even bringing them along a complicated mine cart ride, until they can finally bring her down. When they finally send Deborah hurtling to her death, Helena will reveal to the other two that she helped Derek Simmons breach the President's security in an effort to protect her sister. It's one more odd point to Ada who, receiving a call, parts ways with the others and leaves them with a ring that they can use to leave the underground.
Simmons will send Ada to the lab to find some new information and this will involve a tough route blocked by Whoppers and Napads of all sorts. When she finally reaches the labs she'll find what she's looking for-- a videotape with her name on it. Watching it, she'll find out what the others don't know, specifically that Simmons has created a C-Virus clone of Ada. She quickly deduces that this clone is the one contacting her, puppeteering Neo-Umbrella in an effort to destroy the world. Ada calls the real Simmons, lets him know that she's prepared for the worst, and heads out, blowing up the labs before she leaves the U.S.