GMAT Sentence Correction (SC) | Re: Reporting that one of its many problems had been the recent

Reporting that one of its many problems had been the recent extended sales slump in women's apparel, the seven-store retailer said it would start a three-month liquidation sale in all of its stores.

(A) its many problems had been the recent
(B) its many problems has been the recently
(C) its many problems is the recently
(D) their many problems is the recent
(E) their many problems had been the recent