The correct option is C 16 years of Mendel's death
Answer is option C i.e. "16 years of Mendel's death"
The ‘rediscovery’ of Mendel’s laws in 1900 i.e. 16 years of Mendel's death; was a turning point in modern research of heredity/genetics. According to the traditional view, adopted by many textbooks of genetics, Mendel’s principles were presented in the first half of 1900 simultaneously and independently by three biologists De Vries, Correns, Tschermak.