pattern - What is the next symbol?

I have an IQ question which is giving me a very hard to time to figure out. Please help me find the answer with an explanation.

It seems so simple...

Answer

It will be

C

You can kind of see how it is going. Here is the next two (hollow dots):

It goes

One right, one right diagonal, creating a 45 degree angle.

Here is an extended version:

A more detailed explanation based on elimination:

First you can see that it goes

B R R B B

So it becomes apparent that Red gets two turns of being added, then blue. So now it will be red, ruling out A, D and F.

Next we can see that the new dot is always added somewhere to the right, ruling out E.

So B and C are left. The last thing to note is that the first time a new coloured dot is added, so
B R R B B (R)

the new dot it is always added to the bottom right. So that rules out B giving C. The dot after will be added to the diagonal right, one up and one across from the previous highest dot