I would probably use a checklist (B), because the order in which you complete items on a checklist does not really matter, just don't forget to check them after completing them. A diagram might also be okay, but it depends on what it shows.
C. uses
Uses is the only word that words in this context. The advertisement isn't keeping anything. It hopefully creates a desire in the consumer to buy a product but it doesn't create a technique. It also does intend to convince buyers but it can't intend a technique either. Techniques are used so this is the most accurate and precise replacement for has.
The answer would be 4,686.
To make the outcome more shocking. When the jury finds Tom Robinson guilty, the reader is even more surprised and realizes the wrongness of it.
