问题

________, JackcannevercatchupwithTominthestudyofEnglish. [ ]
A:Howeverhetrieshard
B:Nomatterhowhardhetries
C:Nomatterhowhetrieshard
D:Ashardhetries
B:Nomatterhowhardhetries
C:Nomatterhowhetrieshard
D:Ashardhetries
正确答案是: