When media producers create texts for specific audiences, they are their media.
a. influencing
b. targeting
c. biasing
d. criticizing

B is the correct answer, they are 'targeting' their media, because they are searching for a specific audience, or looking for a target to pay the most attention to. 

Option D: aggressive.

To be assertive he must not either desqualify the persons by telling they are a messy or threatening with losing their employments.

To be assertive he should have asked the empolyees to review the procedures, explain the failures and propose ways to reach the goals.