The converted binary mask 11111111.11100000.00000000.00000000 to decimal is _______________.

(A) 255.255.255.224
(B) 255.255.224.0
(C) 255.224.0.0
(D) 255.64.0.0

255.224.0.0 is the correct answer.
There are only nine possible values in one octet of a subnet mask as shown in the table below.

Binary Mask Octet	Decimal Equivalent	Number of Binary 1s
00000000	0	0
10000000	128	1
11000000	192	2
11100000	224	3
11110000	240	4
11111000	248	5
11111100	252	6
11111110	254	7
11111111	255	8