Option 1 -> Pretense means a false display or act of deception, which is exactly what "charade" means in the context of the assistant performing a misleading show.
Option 2 -> Candor means honesty and frankness, which is the opposite of charade.
Option 3 -> Genuineness means authenticity or being real, which contradicts the meaning of charade.
Option 4 -> Mission means a task or assignment, which doesn't capture the deceptive nature implied by charade.
Hence, Option 1: Pretense -> In the passage, the assistant is performing a "charade" (a deceptive act) by going through motions to create a false impression of legitimate scientific discovery, when the narrator suspects it's actually quackery. Pretense perfectly captures this meaning of false performance or deception. -> correct