Option 1 states that the ELISA test is used as the first and most basic test to detect cancer. However, this is incorrect as the ELISA test is more commonly used to detect if an individual has antibodies related to certain conditions like HIV or Lyme disease, not cancer.

Option 2 suggests that 50% of human beings have Rh+ blood and the remaining 50% have Rh- blood. This is also incorrect as approx. 85% of the world’s population is Rh positive.

So, both the statements I and II are not correct. Therefore, option 4, which states that neither I nor II are correct is the accurate answer for this question.