Answer: In the future, we should be more careful about scheduling
Passage: You scheduled seven conference calls for this morning between 10 and 11 a.m. [2] Generally, the company limits the number of conference calls to three per hour. [3] I’m letting you know that in the future, we should be more careful about scheduling.
Explanation: The third sentence contains unnecessary fillers. The key point in the sentence is to be more careful about call scheduling. 'I’m letting you know that in the future' can be replaced with 'in the future.' By dropping the unnecessary filler 'I'm letting you know that', the meaning does not change but the sentence becomes more concise, has more clarity and is more deliberate.