I would choose B: although it's unusual to see articles about Chinese finds in the press in the West, Dr R's comment suggests that they do exist. And "It's only recently..." equates with "China has just started...".
D seems attractive too; but we aren't told that the Chinese are "secretive". There may have been other reasons for the lack of publication.
But I find the phrasing of answer B slightly odd.
As for the quality of the question...You already know my opinion of the person or panel who sets the questions for these exams!