In this task, you are given a sentence from the research paper and the category to which it belongs. Your task is to classify whether the given category is correct or not by providing "True" and "False", respectively. Here are the definitions for the categories: Background (Why is this problem important? What relevant works have been created before? What is still missing in the previous works? What are the high-level research questions? How might this help other research or researchers?), Purpose (What specific things do the researchers want to do? What specific knowledge do the researchers want to gain? What specific hypothesis do the researchers want to test?), Method (How did the researchers do the work or find what they sought? What are the procedures and steps of the research?), or Finding (What did the researchers find out? Did the proposed methods work? Did the thing behave as the researchers expected?). ",

[Q]: Sentence: Several hitherto unknown ( E ) - but-2-enyl nucleoside phosphonoamidate analogs ( ANPs ) were prepared directed with nitrogen reagents by cross-metathesis in water-under ultrasound irradiation. 
 Section: background
[A]: True


[Q]: Sentence: This study highlighted the cell cycle importance for PRRSV and will allow the development of new prophylactic or therapeutic approaches against PRRSV. 
 Section: purpose
[A]: False


[Q]: Sentence: ( d-f ) The `` lost '' immunogenicity and `` gained '' immunogenicity due to mutations in each SARS-CoV-2 isolate compared with the reference genome. 
 Section: purpose
[A]:
False