创建单线程线程池的是？
A.ExecutorService sTdPool = Executors.newSingleThreadExecutor();
B.ExecutorService fTdPool = Executors.newFixedThreadPool(nThreads);
C.ExecutorService cTdPool = Executors. newCachedThreadPool();
D.ExecutorService schdTdPool = Executors.newScheduledThreadPool(corePoolSize);
正确答案是A