What is the ruling if an illegal bat is detected after a play where R2 scores and B3 advances to second?

The correct choice regarding the situation is that the defense has the option to take the play result or enforce the illegal bat penalty. This scenario involves the detection of an illegal bat after the play has taken place, which means that the defense can choose how they want to proceed.

When an illegal bat is discovered, the rules allow the defense to either accept the result of the play, which includes R2 scoring and B3 advancing to second base, or to enforce the penalty for using an illegal bat. If they choose the penalty, the run scored by R2 might be nullified, depending on specific circumstances relating to the play and the infraction.

Understanding this option is crucial because it highlights the nature of baseball's rules, where a team can choose a course of action that may either maximize their advantage based on the outcome of the play or penalize the offending team for rule violations.