【单选题】

Leanne Holmes

Holmes Gardening
13 FormanDrive
Atlanta, Georgia 30304
August 2, 2010
Dear Ms. Holmes,
I am writing to confirm that your account was settled on July 11. The shipment of gardening tools, which was delivered to your warehouse on July 3, has now been fully paiD、Along with this letter, I have attached an official invoice for your records.
Thank you very much for your prompt payment. I would like to apologize for the lengthy delay between our receipt of the payment and this letter. We normally aim to correspond with clients within two to three working days of a transaction. However, we have recently moved our headquarters fromDunworth Lane to Gribblehurst Street, and many administrative tasks have fallen behind schedule. I hope this has not caused any inconvenience.
I look forward to providing you with additional services in the future.
Kind regards,
Kelly Hendriks
Client Liaison — Optimum Garden Supplies
According to the letter, what caused the delayA、lost shipment
B．An office relocation
C．A、staff shortage
D．A、schedule clash