辨认主题句:
Read the following paragraph and choose the best topic sentence from the four options.
All plans should be in writing and someone should be responsible for central coordination. Hence, risks are lessened and opportunities to save money may arise. Coca-Cola, for instance, requires that all overseas marketing plans be submitted to the central office well in advance. This gives the company a chance to examine the concepts. Previous experiences with similar plans can be reviewed and necessary changes can be suggested. Sometimes central company managers find that similar plans or overseas ventures have failed in the past. Minor improvements tried overseas with success should also be reported. There is no need to reinvent the wheel. Coordination not only reduces the chance of errors, it also provides opportunities to learn improved methods.