Critical Reasoning

there are various versions to this question, but this one is from Officials(Exam Pack 2).
OA: B

Lyme disease is caused by a bacterium transmitted to people by deer ticks. Deer ticks are almost never born infected with the bacterium, but they can pick it up from feeding on an infected host in any of the tick's three successive stage of development: larva, nymph, adult. Once infected, a tick remains infected through any subsequent developmental stages, but since a tick feeds on only one host in each stage, it follows that ______________

A) People can be infected only by being bitten by a tick that is either in larval stage or in the nymph stage
B) People cannot be infected by a tick that picked up the Lyme disease bacterium in the adult stage
C) It is not possible for a person to be infected by a tick that is in the nymph stage or by a tick that was infected with the bacterium while in the nymph stage
D) People infected with the Lyme disease bacterium cannot transmit bacterium to adult deer ticks
E) Only deer ticks that are adults can transmit the Lyme disease bacterium to people

richachampion wrote:there are various versions to this question, but this one is from Officials(Exam Pack 2).
OA: B

Lyme disease is caused by a bacterium transmitted to people by deer ticks. Deer ticks are almost never born infected with the bacterium, but they can pick it up from feeding on an infected host in any of the tick's three successive stage of development: larva, nymph, adult. Once infected, a tick remains infected through any subsequent developmental stages, but since a tick feeds on only one host in each stage, it follows that ______________

A) People can be infected only by being bitten by a tick that is either in larval stage or in the nymph stage
B) People cannot be infected by a tick that picked up the Lyme disease bacterium in the adult stage
C) It is not possible for a person to be infected by a tick that is in the nymph stage or by a tick that was infected with the bacterium while in the nymph stage
D) People infected with the Lyme disease bacterium cannot transmit bacterium to adult deer ticks
E) Only deer ticks that are adults can transmit the Lyme disease bacterium to people

We know that a tic picks up the Lyme disease bacterium by biting an infected host. We know that a tic feeds on only one host at each stage. If a tic picked up the disease as an adult, then we know that the tic won't be feeding again - the adult stage is the final one. Well, if the tic is done feeding, it won't infect anyone with Lyme disease. This is what B gives us.