Answer:
B. and D.
Step-by-step explanation:
Any kind of attempt of trading favors or different means of corruption of the kind explained in the excerpt should be reported.
Before reporting the case, make sure the information you have is true in order not to make the mistakes. The case should be reported completely transparent and honest, in accordance with the situation.
A and C options are wrong because by following them you are becoming the part of the problem yourself, and accepting trading favors which should not be legal. No matter how loyal the advertiser or partner is, you should do what is wrong and not what is best for your own gain.
The option D is also wrong as it does not refer to the legal stances or senior authorities which should solve the case. In that case, you are trying to solve it yourself, possibly to get more gain, and it is likely to make even more mess then honestly and transparently reporting the problem to those who are in charge of the situation.