How can dna be useful in phylogeny?

a. dna from every organism in a class is sequenced to identify genetic mutations that have occurred

b. dna sequences are rearranged to predict how species could evolve in the future

c. dna sequences from different species can be compared, giving us more information about their evolutionary relationships

d. dna isn’t useful in phylogeny, as morphological characteristics are used exclusively in phylogeny

Option C, DNA sequences from different species can be compared, giving us more information about their evolutionary relationships

Explanation:

Phylogeny is the study of evolution of species since ages and  also working out inter species evolutionary relationship.

In molecular phylogeny the DNA and its structure is very essential to work out the evolution of species.  

The information about the structural arrangement of genome, genetic mutation, difference in the nucleotide sequence etc, helps to establish a common ancestry relationship between two or more individual.  

Since all the genetic information is carried by DNA, thus assessment of DNA helps to identify the common thread of evolution  and in this way DNA is useful in phylogeny.