Does it mean immediate right, or right in general?

The answer would be different in both cases.

I am going to assume it means right in general, because “immediate” is not mentioned anywhere.

The total ways in which we can arrange these 8 letters = 8!

The total ways in which we can arrange the letters A,B,C = 3! = 6

Of the 6 total ways in which we can arrange A, B, C; only 1 will satisfy the condition given in the equation, (ie item B is to be placed to the right item of A, and item C is to be placed to the right of item B)

This means only 1/6 of the total arrangements of the 8 letters will satisfy this condition.

Answer = 1/6 * 8! = 6720 (E)