SUM values within a grouped table

[MSSQL] Having a table like:

---------------------------------
|   A   |   B   |   C   |   D   |
---------------------------------
|   1   |  ABC  |  1.3  |  2.5  |
|   1   |  ABC  |  2.7  |  2.5  |
|   1   |  ABC  |  0.5  |  2.5  |
|   1   |  ABC  |  4.2  |  2.5  |
|   2   |  CAB  |  6.3  |  5.7  |
|   2   |  CAB  |  1.9  |  5.7  |
|   3   |  BCA  |  7.7  |  2.5  |
|   3   |  BCA  |  5.8  |  2.5  |
|   3   |  BCA  |  2.1  |  2.5  |
|   4   |  CBA  |  0.3  |  5.7  |
|   4   |  CBA  |  8.2  |  5.7  |
---------------------------------

What would be the best approach to obtaining a resultset like:

-----------------------------------------
|  c1   |  c2   |  c3   |  c4   |  c5   |
-----------------------------------------
|   1   |  ABC  |  8.7  |  2.5  |  11.2 |
|   2   |  CAB  |  8.2  |  5.7  |  13.9 |
|   3   |  BCA  |  13.5 |  2.5  |  16   |
|   4   |  CBA  |  8.5  |  5.7  |  14.2 |
-----------------------------------------

Where, t1 is grouped A, t2 is grouped B, c3 is the SUM of C, c4 is grouped D and c5 is c3+c4

So as you can see A, B and D are fixed values being repeted by the JOIN that generates the table, Ideally this values would be grouped and the values in C will SUM.

I refer myself to this question but didn't help much.

Any ideas are appreciated.