Where do teenagers get all the money they need to make purchases? i noticed several new stores had opened up at the local mall. most of these new stores focused on teenage and young consumers. yesterday i went shopping. this paragraph lacks
a. proper conventions
c. good word choice
b. organization
d. voice

What the paragraph lacks is:

b. Organization.

Although proper conventions are followed, there is good word choice and a voice (active voice- first person singular), the ideas are expressed in a chaotic, confusing order, as in one of those "unscramble the sentences" exercises. If properly organized, the paragraph would go like this:

Yesterday I went shopping.  I noticed several new stores had opened up at the local mall. Most of these new stores focused on teenage and young consumers. Where do teenagers get all the money they need to make purchases?

a and b are the correct answer to what your looking fior