Question: Extract the answer to the following question from the movie plot. If the question isn't answerable, please output "Can't answer". Question: What subject did Jessica Martin teaches in the movie? Title: Cellular Movie plot: The film opens with Jessica Martin, a high school biology teacher, talking to her son Ricky, while escorting him to the school bus. After she returns home, mysterious assailants enter her home through the back door, kill her house maid, kidnap her and confine her in the attic of their safe house. Ethan, the gang leader, smashes the only telephone in the attic to prevent her from contacting anyone. She has no idea who the kidnappers are or what they want. She pieces together the broken phone to randomly make a connection. She finally reaches the cell phone of Ryan who has just been dumped by his girlfriend for being too irresponsible. He takes it as a joke, but Jessica persuades him to go to the police. At the police station, Officer Mooney tells him to go to the detectives on the fourth floor. He begins to lose the signal in the stairwell, and must turn back to avoid losing the connection.Meanwhile, Ethan returns to the safehouse and asks Jessica about something she doesn't know. When Jessica tells him that she doesn't know, he tells her that he is going to get her son. Ryan, who overhears them, realizes how serious the kidnapping situation is. After Ethan leaves, she tells Ryan to get to her son's school before they do. Unfortunately, he is too late and her son, Ricky, is kidnapped and he quickly chases them by stealing a car owned by a school security officer. Because his cell phone's battery is dying, he drives to a shop for a charger. After being repeatedly redirected from counter to counter, he uses a gun from the security vehicle to hold up the store at gun-point to obtain the device.Sgt. Mooney, meanwhile, decides to check on the kidnapping claim that he received. He uses the Department of Motor Vehicles records to find the address of Jessica, but when he comes to her house, a woman meets him, telling him that she is Jessica and that everything is fine. Believing it to be a false alarm, he leaves. It is revealed that the woman is Dana Bayback, an accomplice of the kidnappers.Ethan returns to the safe...
Answer:
Biology