TPO17 SYMBIOTIC RELATIONSHIPS - 英檢

想要請問一下為什麼第五題答案是A 我是選D 可是我不知道D為什麼錯...
麻煩大家指導一下 感謝!

5. Which of the following can be concluded from the discussion
in paragraph 3 about the Australian rabbit population?
○Human intervention may alter the host, the parasite, and the relationship
between them.
(我覺得最後一句 natural selection stabilized this host-parasite
relationship. 意思不是說 自然選擇還是會讓這個情況穩定-->那人類應該沒辦法改變?)

○The risks of introducing outside organisms into a biological
community are not worth the benefits.
○Humans should not interfere in host-parasite relationships.
○Organisms that survive a parasitic attack do so in spite of the natural
selection process.


Paragraph 3: At times, it is actually possible to watch the effects
of natural selection in host-parasite relationships. For example,
Australia during the 1940 s was overrun by hundreds of millions of European
rabbits. The rabbits destroyed huge expanses of Australia and threatened the
sheep and cattle industries. In 1950, myxoma virus, a parasite that affects
rabbits, was deliberately introduced into Australia to control the rabbit
population. Spread rapidly by mosquitoes, the virus【devastated】 the rabbit
population. The virus was less deadly to the offspring of surviving rabbits,
however, and it caused less and less harm over the years.
Apparently, genotypes (the genetic make-up of an organism) in the rabbit
population were selected that were better able to resist the
parasite. Meanwhile, the deadliest strains of the virus perished with their
hosts as natural selection favored strains that could infect hosts
but not kill them. Thus, natural selection stabilized this
host-parasite relationship.

--