Cannot eliminate Paste Options pop-up button

I have found instructions on the Net for stopping that rather intrusive 'Paste Options' pop-up button appearing in Excel 2003, 2007 and 2010 (I think; or it might have been 2011). But I have Excel 2008, and none of the instructions I have found applies. I cannot find a Microsoft Office button (other than the icon of the folder in Applications); nor is there 'Options' in the File menu. I use a Mac mini (Intel) with OS 10.8.4 (Mountain Lion).

I should be very grateful for advice.

Thanks very much, Martin Wilson. The curious thing is that Prefs.was the first place I looked at and unchecking those buttons was the first thing I tried, but it didn't seem to work. I've now tried again, and it has worked. Total mystery! But all's well that ends well, so thank you again.