Mutations are considered directionless because

The correct option is B these can be useful, harmful or neutral
According to the Hugo de Vries theory of evolution, evolution can occur in a single generation due to mutations which are random, discrete and directionless. He believed that single step large mutations (saltations) can form entirely new species in a single generation.

Mutations refer to large and discontinuous inheritable changes in the genetic material that result in the expression of observable characters which are extremely different from each other without having any intermediate form. As the mutations are produced occasionally without prior precedent, they are termed as discontinuous heritable changes in the genetic material.

Mutations can occur in any individual of a population at any point of time. Mutations appear suddenly and the consequences of a mutation have no influence whatsoever on the probability that this mutation will or will not occur. For instance, beneficial mutations do not happen more often simply because an organism could benefit from them. Hence mutations are considered to be random.

The outcome of the mutations cannot be predicted. They can be useful, harmful or have no effects at all on the organisms. Hence, they are considered directionless.

For example, mutation in bacteria producing antibiotic resistance strains (useful mutation).

Mutations leading to the formation of non-functional proteins hindering normal metabolic functions like in case of sickle cell anemia, colour blindness (harmful mutation).

Sometimes mutations cause changes in the nucleotide sequence of a gene with no observable effect on the phenotype as they do not disturb the genetic code (neutral mutation).