Prior to the destruction of the Second Temple in 70 CE, Jewish Diaspora communities existed primarily in areas surrounding the Mediterranean and the Near East. Among the options you provided, Central Asia is the most historically relevant location regarding Jewish communities in the broader sense, as there were movements of Jews into areas of Central Asia, though the presence was not as prominent as in the Mediterranean.
Great Britain and Japan did not have significant Jewish communities until much later in history. Southern Africa also did not have a notable Jewish presence until the modern period.
Therefore, of the options listed, Central Asia is the most accurate in the context of historical Jewish Diaspora communities prior to the destruction of the Second Temple.