Mendel's work remain unrecognized for long time due to

$I.$ Communication was not easy

$II.$ Concept of factors which did not blend was not accepted

$III.$ Use of mathematics to explain biological problem was unacceptable

$IV.$ He could not provide any physical proof for the existence of factors Choose the right combination

• A

  $I$ and $II$

• B

  $II$ and $III$

• C

  $III$ and $IV$

• D

  All of these