Answer:
Defenitely b, fossils, I don't think any of the others are right, But I could be wrong.
How are new alleles created? Occasionally, DNA mutations occur in germ cells – cells destined to become eggs or sperm. In this case, the DNA mutation is copied into every new cell of the growing embryo following fertilisation. ... If the mutation affects a gene, it will result in a new version of that gene – a new allele.
It reproduce by a process call Binary Fission