Hi Miriam,
Much of the specifics have been answered already - however I would like to add a crucial success parameter based on my observations.
Many candidates find the qualitative (multiple-choice) answers quite tricky. The options that are given, all seem good choices.
The crucial trick is to pay laser-focused attention to the exact words in the question.
For example, if A wants to respond to B & C's merger - then what information should they analyse?
In this case, first understand what are the competitive improvements for BC after the merger. Then see what are the changes required in A to improve A's competitiveness. Then see which information from the given options can help in analysing for those changes.