(A) is the correct answer.
Issue: Whether a federal court can exercise jurisdiction over a case that is pending in state court and invokes both federal and state law.
Rule: Abstention is the avoidance of unnecessary adjudication of a constitutional issue. Federal courts will resolve a constitutional question only if there is no alternative basis on which the controversy can be resolved. If an action might be resolved in state court, the federal court may exercise abstention to allow the state court to settle the issue.
Analysis: Since the validity of the state statute might turn on state law, the state court may resolve the matter without ever addressing the federal law. The federal court should thus exercise abstention to allow the state court to settle the issue.
(A) is correct because the court would likely exercise abstention to avoid hearing a case that may be resolved by the state court.
(B) is incorrect because although the Eleventh Amendment prevents federal courts from entertaining claims against a state by its citizens or by those of another state, it does not prevent the courts from hearing a challenge to the validity of a state statute. Thus, the Eleventh Amendment is not applicable here and would not bar the court from hearing this case.
(C) is incorrect because the rejection of the man’s application was based on the state law that is being challenged. An order enjoining the state from enforcing the statute could result in the hiring of the man. The question is therefore not moot.
(D) is incorrect because a person has standing to challenge a statute if a judicial determination would prevent a concrete and direct injury to him. Since a favorable decision could result in the man being hired, he does have standing.