How to float DIV to bottom under PARENT DIV

while doing development i got into this interesting task where i need to have my DIV B in bottom right.

there are different ways
1. giving top margin
2. giving bottom margin
.etc .etc….
finally after some browsing on net got superb answer which solves my problem.
its here in pic, if any one has still question please feel free to ask

HTML 5 – HyperText Markup Language Version 5

HTML 5 – Hypertext markup language version 5 is the next major version of the Browser’s htm language. This is going to make our world of internet really very fast.

Basically this will have number of new elements, such as