Keep? maintain? ......
(A) keep (B) maintain
The answer is "B"
However, I consider A to be sensible to the question above because I checked up the definitions for the two words and found that they are similar in this way.
keep(look at the definition 4) >>http://www.ldoceonline.com/dictionary/keep_1
maintain(look at the definition)>>http://www.ldoceonline.com/dictionary/maintain
Personally, if we are not arguing about the detail, we may be welcome to the two words in this regard.