Last Sunday morning, when I was having a walk in the park near my home, I came across a crew make a new film with one of my favourite actor. I didn’t have my camera with me at time, but I rushed back home to get . Unfortunately, by the time I got back, theyhave finished the scene and the actor couldn’t be seen everywhere. I was really disappointing and about to leave when he walked out a building. He was right there in the front of me! I couldn’t believe my luck-not only did I had my photo taken with him, but he signed his name on my shirt!

一元硬币的外观有银白色的金属光泽，一些同学认为它是由铁制成的．在讨论时，有的同学提出“我们可以拿磁铁来吸一下”．“拿磁铁来吸一下”属于科学探究中的（　　）

A．实验

B．假设

C．观察

D．做结论