They did not pay any attention 和They did't notice him有什么区别吗

They did not pay any attention 和They did't notice him有什么区别吗
这是新概念英语第二册第一课的内容
A Private Conversation
Last week I went to the theatre.I had a very good seat.The play was very interesting.I did not enjoy it.A young man and a young woman were sitting behind me.They were talking loudly.I got very angry.I could not hear the actors.I turned round.I looked at the man and the woman angrily.They did not pay any attention.In the end,I could not bear it.I turned round again,‘I can’t hear a word!’ I said angrily.
‘It’s none of your business,’ the young man said rudely.‘This is a private conversation!’
看了回答课后的一个选择题:
The wtiter turned round.He looked at the man and the woman angrily_____.
(a).and they stopped talking (b)but they didn't stop talking (c)but they didn't notice him (d) but they looked at him rudely