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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def offer_simple(pool, answer, rationale, student_id, options):
 """ The simple selection algorithm. This algorithm randomly select an answer from the pool to discard and add the new one when the pool reaches the limit """

    existing = pool.setdefault(answer, {})
    if len(existing) >= get_max_size(pool, len(options), POOL_ITEM_LENGTH_SIMPLE):
        student_id_to_remove = random.choice(existing.keys())
        del existing[student_id_to_remove]
    existing[student_id] = {}
    pool[answer] = existing