To find the remainder when a number in one base is divided by a number in another base, we need to convert both numbers to the same base. In this case, we need to convert (3264) from base 7 to base 10.
To convert (3264) from base 7 to base 10, we can use the following formula:
$(3 \times 7^3) + (2 \times 7^2) + (6 \times 7^1) + (4 \times 7^0)$
Simplifying the equation, we get:
$1029 + 98 + 42 + 4 = 1173$
So, (3264) in base 7 is equal to 1173 in base 10.
Now, we need to find the remainder when 1173 is divided by 8 in base 10.
To find the remainder, we can divide 1173 by 8:
$1173 \div 8 = 146 \text{ remainder } 5$
Therefore, the remainder when (3264) in base 7 is divided by (8) in base 10 is 5.
The correct answer is option D.