【单选题】下列代码的执行结果是f=open('writetest.txt','a+')f.write('This is a test file')f.write('Please print this file')print(f.readline())f.seek(0)print(f.readlines())
A.
This is a test file This is a test file Please print this file
B.
This is a test filePlease print this file This is a test file Please print this file