The argument in the stimulus uses the following logical pattern:
some/many movies starring famous actors -> do well ~star famous actors -> ~ do well
many, few, some are all logically equivalent quantifiers
some As are Bs not As are not Bs
(B) has a similar pattern: many gardens w bee balm -> produce abundant crop ~ bee balm -> ~ crop
The issue with (D) is that the argument in the stimulus involves a logical statement "movies..WILL do well" whereas in (D) it merely implies a possibility "can" be useful. Statements that use language that simply implies a possibility "may" "can" are not logical statements and cannot be diagrammed as such. Note that the consequent in (D) has the same flaw - "might sometimes be more difficult." To parallel the stimulus, (D) would look similar to:
Many/ some teachers using visual aids will effectively teach math. Using no visual aids will likely result in ineffective math lessons.
Let me know if this helps and if you have any other questions.