Disagreement With Neet UG 2019 Revised Answer Key (chemistry question)

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The answer of the following question given in initial answer key (dated 29/05/19) was correct whereas the correctness of answer given in the revised answer key (dated 5/6/2019) is doubtful/debatable. 

 Q: Under isothermal condition, a gas at 300K expands from 0.1L to 0.25L against a constant external pressure of 2 bar. The work done by the gas is : (given 1L bar =100J)

1. 5kJ,   2. 25J,   3. 30J,   4. - 30J .. 

In the initial answer key, correct option was given as - 30 J while in the revised answer key it's given as 30J..  (ref Ncert chemistry part I, class XI,  pg 157  - " Similarly if work is done by the system w will be negative"  ; ref NCERT chemistry part I  class XI,pg 159 - " .. conventional sign for what, which will be positive. It indicates that in case of compression, work is done on the system". So that implies expansion work is done by the system and is negative) . 

So we earnestly request you to review the answer before publication of final result..