The first alternative is correct (A).
The relations of cause and effect are applied when one phenomenon is able to explain the event of another phenomenon. For example, in item (B): recycling programs (the cause) reduce local waste production (effect).
In order to discuss the problem of hunger in underdeveloped countries, many causes need to be analyzed, that is, there is not only one phenomenon that causes hunger, but several, such as poverty, politics, lack of jobs.
