I go for C.
Argument says that let's say 5 out of 10 would be D(doctor) (50% probability) from those whose parents are D and 400 out of 1000 (40% prob)of those whose parents aren't. Finally we have 405 D of whom obviously much more that 70% don't have parents D.
OA is C.
This CR tests your understanding of numbers and scope shifts.
Whenever we see statements like more likely
in CR we have to remember that it is testing some form of probability. So what Choi is saying is not that the children of doctors are guaranteed
to earn doctorates, nor does he claim that they are likely
to earn doctorates. He simply says that they are more likely
(a higher probability) to receive a doctorate than those who do not have a parent with doctorates.
So if you pick numbers, as kandid has done above, you'll see that Hart's stmnt is actually consistent with Choi's claim.