Choices, Choices

M3 - Choices, Choices is a mission in Deus Ex: Human Revolution - The Missing Link DLC.

Disrupt the gas dispersal
Upon passing throguh security lock to the lab complex, Adam Jensen finds Netanya Keitner lethally wounded in the corridor leading to Detention Block B. She tells him that Pieter Burke has launched a scorched earth protocol to get rid of all possible witnesses by flooding the prison cells and sea-level laboratories with deadly gas. A control in the main prison command tower allows to redirect the gas output either from the detention cells or the sea-floor laboratory. A mysterious voice with a russian accent tells Adam to choose between saving the prisoners or Dr. Tiffany Kavanagh, who uncovers Belltower's illegal experiments. There is a way to complete both tasks, see the Notes section below.

Save the prisoners
Diverting the gas to the seafloor lab will kill Dr. Kavanagh and prevent information on Belltower's activities getting out. Choosing to save the prisoners instead of letting Burke commit mass murder will reward 2500 XP. The scrambled voice orders Adam to unlock the prison cell doors using the security terminal on the floor above.

Save doctor Kavanagh
Saving Dr. Kavanagh will reward 1500 XP, 1000 XP less than saving the prisoners, but it will allow her to uncover the Belltower's Hyron Project and the illegal science performed.

Get Kavanagh off the base
If he chose to save Dr. Kavanagh, the mysterious voice will tell Adam to unlock the submersible for her escape by accessing the security mainframe on the control tower's upper floor.

Disengage the lockdown and return to base
In any case, Adam will have to disable the lockdown at the command tower's security mainframe, before entering the ground floor security scanner to persue Burke. While the scan is performed, Burke's voice will disclose that in order to get on the ship to Megan Reed's location, Adam will have to confront him.