Answer: OPTION E
Explanation:unequal crossover usually leads to duplication or deletion of chromosome. In this case,. A DNa strand is deleted and replace usually by another DNA strand which is mostly a duplicate from a sister chromatid and this process leads to Gene families been produced beause one is deleted and again and again duplicate is produced on the same place (2 product formation). It is a form of chromosomal crossing over that exists between homologous sequence which were initially not paired together. In Gene duplication and mutation in organism, unequal crossover is said to be the pioneer or chief cause of it with Gene conversion beside it.