With no explanation, chose the best option from "A", "B", "C" or "D". Smith to provide a bare legal conclusion without explaining the criteria he used to reach that conclusion. Because we agree with the defendants that the district court erred by admitting this portion of Mr. Smith’s testimony, we must determine whether this error requires reversal of the defendants’ convictions. “In order for an error of this nature to be reversible, the error must affect substantial rights and must result in actual prejudice. Error which does not rise to the magnitude is harmless.” Evans ex rel. A.E. v. Indep. Sch. Dist. No. 25, 936 F.2d 472, 476 (10th Cir.1991). “The question is not whether, omitting the inadmissible statements, the r r admission of evidence was prejudicial where the erroneously admitted evidence was “extremely compelling”); Specht, 853 F.2d at 808-09 (<HOLDING>); United States v. Sanders, 928 F.2d 940, 942

A: holding that defense counsels failure to object to testimony did not warrant a new trial because there was no prejudice from admission of the testimony
B: holding that the admission of expert testimony was prejudicial where the testimony was pervasive
C: holding that erroneous admission of improper and prejudicial evidence did not require reversal because the jury would have returned a verdict of guilty against the defendant even without the prejudicial testimony
D: holding that improper admission of expert testimony was harmless in light of otherwise overwhelming evidence and fact that testimony covering substantially the same area was introduced without challenge
B.