National Survival: I, the Only Zombie

[National Survival + Only Zombie + ALS Genius + Counter Routine] Ten billion people on earth have traveled through the apocalypse, and the system announced: If all the zombies are eliminated, they can go home. I looked down at my right hand - black lines spreading across it. I'm the only zombie. It is also the only key to pass the level. But no one knows that in my last life I suffered from late-stage ALS and could not die. Now the system tells me: If I don't infect humans, I will be sent back to the hospital bed to die. Infect humans and become monsters. I choose... To let the whole world play a game with me. There is a mentally ill person driving a food truck next to me. He asks me every day: "Which one do you want to infect today?"