Which of the following should be the FOURTH sentence after rearrangement

Directions (next five questions) : Rearrange the given six sentences/group of sentences (A), (B), (C), (D), (E) and (F) in a proper sequence so as to form a meaningful paragraph and then answer the given questions.

1.        “It’s undefined. No one knows if you reach it. It gives the flexibility to revise it later,” he added.
2.         Of late, doubts are being raised concerning the health of the world’s second-largest economy, China.
3.         This change is relatively small but suggests that the country’s effort to meet its official growth target was together was tougher than it seemed.
4.        It comes as worries grow that China will struggle to reach this year’s goal of ‘about’ 7%.
5.         “That’s the beauty of using ‘about’ in your targets,” said HIS Global Insight economist Brian Jackson.
6.         The reasons for these doubts stem from the fact that the country revised its 2014 growth rate to 7.3% from 7.5% due to a weaker-than-reported contribution         from the service sector.

Directions (next five questions) : Read each sentence to find out whether there is any grammatical mistake/error in it. The error, if any, will be in one part of the sentence. Mark the part with error as your answer. If there is no error. Mark (5) as your answer.