A language model is generating a sentence completion. In one configuration (Scenario A), it considers multiple potential next words but only keeps the single most probable word to continue the sentence. In another configuration (Scenario B), it keeps the top 3 most probable words at each step. Scenario A produces the sentence 'The cat sat on the mat.' Scenario B is able to produce the more creative sentence 'The cat sat on the windowsill.' What is the primary drawback of the process used in Scenario A, and how does it relate to which candidate words are kept versus discarded at each step?