A is correct. Companies pursuing cost leadership must be able to invest in productivityimproving capital equipment in order to be low-cost producers and maintain efficient operating systems. 

B is incorrect. Establishing strong market research teams to match customer needs with product development is appropriate for companies pursuing a differentiation strategy. 

C is incorrect. Defensive pricing is appropriate when the competitive environment is one of low rivalry, not high.

B is correct. In a semi-strong-form efficient market, prices adjust quickly and accurately to new information. In this case, prices would quickly adjust to the merger announcement, and if the market is a semi-strong-form efficient market, investors acting after the merger announcement would not be able to earn abnormal returns. Therefore, the market is not semi-strong-form efficient. A market that is not semi-strong-form efficient is also not strong-form efficient. Thus, violating the semi-strong-form efficiency also implies violating the strong-form efficiency. However, the market could still be weak-form efficient because past prices are not being used to make abnormal profits. Thus, we cannot say that the weak-form market efficiency has been violated. 

A is incorrect. A market that is not semi-strong-form efficient is also not strong-form efficient. Thus, violating the semi-strong-form efficiency also implies violating the strong-form efficiency. 

C is incorrect. The market could still be weak-form efficient, as past prices are not being used to make abnormal profits. Thus, we cannot say that the weak-form market efficiency has been violated.