Here, the medium lacks compound, but it has growth (+), therefore this stain has received genes. The medium lacks compound, but it has growth (+), therefore this stain has received genes. Likewise, the medium lacks compound, but it has growth (+), therefore this stain has received genes.
The gene order is as follows:
(Note: the gene b is at no time cotransduced with other genes, hence it very distant from other genes)
Thus, the gene order is