A, B, and C are all correct. The Aztecs believed the Spanish were fulfilling a prophecy from one of their gods (I forget which, but the god had light skin and would return from over the sea) and they welcomed them with gifts. The Spanish were carriers of small pox, which the Aztecs had no natural defense against.
I have gone back and forth between 50mg and 100mg Toprol xl. My dr just prescribes the 100 mg tablet and tells me to split it in half. As Lenin said just don't crush the half or chew it and you should be fine. I have split mine for a long time.
Talk it over with your cardiologist to see if you can try 50 mg XL once a day. If she agrees you can split you 100 mg tablets - if necessary buy a pill splitter. Here I assume you'll get a chance to see what 50 mg will do and I further assume you didn't have serious side effects at the 25 mg level.