IMO B. Please post the OA, if my answer is correct, I'll post my reasoning.

nitinrajasingh wrote:Defendents who can afford expensive private defense lawyers have a lower conviction rate than those who rely on court-appointed public defenders. This explains why criminals who commit lucrative crimes like embezzlement or insider trading are more successful at avoiding conviction than are street criminals.

The explanation offered above would be more persuasive if which one of the following were true?

[a] Many street crimes. Such as drug dealing, are extremely lucrative and those committing them can afford expensive private lawyers.
Most prosecutors are not competent to handle cases involving highly technical financial evidence and have more success on prosecuting cases of robbery or simple assault.
[c] The number of criminals convicted of street crimes is far greater than the number of criminals convicted of embezzlement or insider trading.
[d] The percentage of defendants who actually committed the crimes of which they are accused is no greater for publicly defended than for privately defended defendants.
[e] Juries, out of sympathy for the victims of crimes, are much more likely to convict defendants accused of violent crimes than they are to convict defendants accised of "victimless" crimes or crimes against property

The correct answer is choice D.

The author is assuming that the discrepancy in conviction rates isn't due to the possibility that private defendants are simply less likely to be guilty than publicly defended defendants.

Choice D strengthens the argument by removing this possibility.

We can use the Kaplan denial test. What if the percentage of defendants who actually committed the crimes of which they are accused IS greater for publicly defended than for privately defended defendants? Then, this would certainly weaken the argument as it would point to an alternative explanation for the discrepancy in conviction rates. Because the denial of choice D weakens the argument, choice D itself must be a strengthener.

In order for us to think choice B is correct, we would have to assume that the prosecutors selected to prosecute lucrative crimes are the ones who are not competent.

The answer is indeed D. Thanks Testluv

In my opinion D is the most logical one.