Mendel published his work on the inheritance of characters in 1865, but it remained unrecognized until 1900. Choose the correct reasons for this from the options below.
a) He could not provide any physical proof for the existence of factors.
b) His concept of factors being stable, discrete units that controlled the expression of traits did not find acceptance by his contemporaries.
c) Mendel’s approach to using mathematics to explain biological phenomena was not new.
d) Communication was not as easy as it is now.