Which of the following is not a characteristic of organic farming?
a.
the use of natural fertilizers
b.
the use of crop rotation and mulch
c.
the use of insects and birds to reduce pests
d.
the use of genetic modification to avoid using pesticides

D the answer to your problem 

The investiture controversy began as a power struggle between pope gregory vii (1072–85) and henry iv, holy roman emperor (1056–1106).[2] a brief but significant struggle over investiture also occurred between henry i of england and pope paschal ii in the years 1103 to 1107, and the issue played a minor role in the struggles between church and state in france, as well.by undercutting the imperial power established by the salian emperors, the controversy led to nearly 50 years of civil war in germany, and the triumph of the great dukes and abbots. imperial power was finally re-established under the hohenstaufen dynasty. historian norman cantor:

Answer (a) the itcz comes overhead for part of the year; i believe this is correct,plz check first; ///