This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Types of Genetic Disorders, Subject name: Pediatrics
[{'content': 'Which is the longest chromosome? \nSelect and explain. \nA. Chromosome 1, B. Chromosome 21, C. Chromosome 14, D. Chromosome X', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Chromosome 1 is the longest chromosome. In a karyotype, chromosomes- arranged according to their length and banding features. Chromosomes 1 to 22 are arranged according to their length, in the descending order. Chromosome X is longer than the Y Chromosome.', 'role': 'assistant'}]