As is mentioned in the card, the limitation of the research paper mainly lies in that_

Asismentionedinthecard,thelimitationoftheresearchpapermainlyliesinthat_____.

A.thedataanalysisishardlyreliable

B.theresearchsampleisnotwideenough

C.thefindingsareofnopracticalvalue

D.theresearchmethodisout-of-date

从文中“thesurveysamplewasrestr ictedtomid-levelmanagement(此次调查只局限于中层管理人员）”可知答案为B。