How do the changes in the narrator's relationship with Miss Chavez affect the plot? A
The more the narrator helps Miss Chavez, the more she learns about her past.

B
Every time they talk, the narrator learns more about the Dust Bowl.

C
As they become closer, the narrator wants to help Miss Chavez even more.

D
Every time the narrator visits Miss Chavez, she learns more about yard work.

C

Explanation:

You'll just have to reread the book. It says. :)

the present continuous is a verb tense which is mainly used to indicates that an action is in progress at the moment of speaking.  

it is formed using: person + verb to be (am/is/are) +verb + - ing form  

example: i am studying at this moment .

in addition, the present continuous is also used in order to express things that will or will not happen in the near future.

example: i am having dinner with some friends tonight.

the speaker sometimes   uses it   to express that an action is repeated and it causes irritation on the part of the speaker

example: my sister is constantly complaining about everything.