A testcross of trihybrid Drosophila produced the following phenotypes and number of offspring. A table showing phenotype and the number of offspring with each phenotype is below. A plus sign is used for wild-type phenotype; a letter indicates the mutant phenotype for that gene. +++abc++cab++b+a+c+bca++6696531211392280221532 -Without performing any calculations,which of the following is the gene order?