Question

weeping willows do not weep

1. although some scientists have argued otherwise, plants cannot necessarily feel pain. plants do not have a brain or a central nervous system which can allow this to happen. humans and animals sense pain through sensory nerve cells, which pass information from the senses in order to smell, see, hear, taste, and touch. plants may show a response, but that doesnt mean they feel pain. plants process information only at a cellular level. they do not have a complex system like humans and animals.
2. research shows that when an aphid attacks a leaf, it sends an electrical signal that travels from leaf to leaf. it tells the plant to start protecting itself. this communication doesnt actually mean that the plants sense pain. plants recognize what is happening and even warn of the attack to other parts of the plant. however, this is different from feeling pain.
3. pain is a defense mechanism. in other words, it is a reaction. plants do not have a biological need to feel pain. plants cannot protect or defend themselves, therefore, they cannot feel pain. there are some exceptions, like the venus flytrap, which shows plants more advanced sensory abilities. a plant called mimosa pudica closes up when someone touches its leaves. this is still limited to processing signals and not necessarily feeling anything. venus flytraps and mimosa pudica have a specific organ for movement. it is called a pulvinus. other plants do not have it. however, even pulvinus only reacts to touch at a cellular level.
4. when we think that mowing the lawn or cutting a branch is inflicting pain, we are transferring human feelings to plants. uprooting a carrot or trimming a hedge is not hurting a plant. therefore, you shouldnt doubt yourself while biting into an apple. a wilting plant or a chewed - up leaf is not weeping in pain. plants do not suffer. their cycles simply begin in life and end in death.

as it is used in paragraph 3, which phrase defines mechanism?
a. a process of achieving a result
b. a process that is painful
c. a process that plants go through
d. a process of working like a machine

Explanation:

En el párrafo 3, se define "defense mechanism" como "a reaction" (una reacción) relacionada con la defensa. Las plantas no tienen necesidad biológica de sentir dolor ni pueden defenderse, pero el término se refiere a un proceso dirigido a un objetivo (la defensa), lo que corresponde a "un proceso para lograr un resultado".

Answer:

A. A process of achieving a result