Step 1: Analyze the statements.
Statement A says that if there is a shortage in the production of onions, the price of onions will go up.
Statement B confirms that the price of onions has gone up.
Step 2: Evaluate the conclusions.
Conclusion I states that there is a shortage in the production of onions, which logically follows from the fact that the price of onions has gone up, as per Statement A. Thus, Conclusion I follows.
Conclusion II about onions being exported does not logically follow from the statements given. It introduces a new idea not supported by the statements. Therefore, Conclusion II does not follow.
Final Answer: The correct answer is (a) if only I follows.