Some surveys show that about three quarters of small businesses give money
to charities, donating on average about six percent of their profits.
Quote:
A.) charities, donating on average about six percent
- looks perfectly fine: -ING modifier modifies the action of the preceding clause, providing HOW aspect.
Quote:
B.) charities, and it is average to donate about six percent
- I haven't spotted any obvious errors with option B, just it conveys the same meaning in more words and some might say that with a small shift in meaning (?)
Quote:
C.) charities and on average do they donate about six percent
- there is no comma to connect two independent clauses connected with "and". Besides this error, this option provides the same meaning but in less concise manner than original sentence. So, A still wins.
Quote:
D.) charities,
so that they average donations of about six percent
use of "so that" changes meaning
Quote:
E.) charities; the average is to donate six percent
- no good reason for elimination, but seams as a shift in meaning too.