执行该程序段后，下列语句能正确输出单词"apple"出现次数的是？( )
>words ["apple", "pear", "apple", "apple", "keep", "day"]dic={}for i in words:if i in dic:dic[i] = dic[i] + 1else:dic[i]=1
print(dic[O])
print(dic(0))
print(dic["apple"])
print(dic("apple")