Indian Institute of Foreign Trade 2012 Solved Paper

We use 'between' to refer to two things which are clearly separated. We use 'among' to talk about things which are notclearly separated because they are part of a group or crowd or mass of objects
Thus, in i Between should be used and Among should be used in iv
In ii the tense is 'present perfect' and the starting point of time of the action is mentioned thus, the correct word use in ii will be ‘since’
In iii the tense is simple past and the starting point of time is mentioned—January and thus, we should use ‘from’.If in iii instead present perfect tense was used like in ii then we would have to use 'since'.
Inv 'six months', a period of time, warrants the use of 'for'.
The only option in which all of this is correctly used is option D.
Hence, option D is the correct answer.