XYZ company has many overseas development sites and a large client base spread

 
XYZ company has many overseas development sites and a large client base spread across 30 countries. 
Respond to the following in a minimum of 175 words:  
What challenges do you foresee in the OD process when the OD practitioner and client come from different cultures? How do you think an OD practitioner should approach an engagement where the cultural environment is unfamiliar?