This is for language arts but i don't have this option

Which foundational concepts in biology were merged in the modern synthesis?               a.  darwin's theory of evolution and chargaff's rules of base pairing    b.  darwin's theory of evolution and watson's and crick's structure of dna    c.  darwin's theory of evolution and mendel's ideas of heritability    d.  darwin's theory of evolution and hershey's and chase's proof of dna as genetic material