With reference to the above passage [Passage 1 on climate change and crop diseases], the following assumptions have been made: I. Global climate change can result in the migration of several plant diseases to new areas. II. Scientific understanding of the wild relatives of our present crops would enable us to strengthen food security. Which of the above assumptions is/are valid?

Assumption I is directly supported by the passage which says climate changes 'will make some plant infections more common in all climatic zones,' implying migration of diseases to new areas — this is a valid underlying assumption. Assumption II about scientific understanding of wild relatives is not mentioned or assumed in the passage; the passage discusses the loss of genetic variation due to breeding but does not assume that studying wild relatives would strengthen food security. Hence only assumption I is valid. Answer is (a) I only.