Answer:
A) histone coding genes
Step-by-step explanation:
Histones are the proteins involved in the packing of DNA in eukaryotes. They are positively charged proteins and are not found in bacteria. To analyze the evolutionary relationship in a gene between eukaryotes and bacteria, one must choose the gene present in both of them. The tRNA, rRNA and hexokinase encoding genes are common to both bacteria and eukaryotes. Therefore, one of these genes may be chosen for the study. However, histone encoding genes are not present in the genomes of bacteria. Therefore, the study of the histone encoding gene would not be useful for the mentioned purpose.