阅读下列短文，从下面每小题的A、B、C、D四个选项中选出最佳选项。

    What's it all about?

    OneSmallDeed.com is a website which lets the world know the good deeds（行动）they have done and to encourage others to do the same.

    Who are we?

    We are not a big organization, but just a group of people who wanted to find a way to make the world a nicer place. We live in London and come from different countries and cultures. The one thing we have in common is that we are kind and giving people who want to see more people like us.

    Want to join?

    All you need to do is just a small good deed as often as you can do. If you want to encourage others, then post your deeds on our website.

    Here are some suggestions for you to get started:

    1  Open the door for someone 

    2  Give up your seat on the train or bus for someone who needs it more than you.

    3  If somebody asks for your help and you are really busy, find a way. 

    4  If someone in need, like a man in a wheelchair to get across the street, help them. 

    5  If you see someone crying, ask if you can help.

已知函数$y=A\sin \{\omega x+\phi )+B$($A>0,\omega >0,\left|\phi \right|<\frac{\mathrm{\pi }}{2}$)的周期为$T$，在一个周期内的图象如图所示，则正确的结论是（     ）