1 is CORRECT. Adding a front and back end zero to the number (11011.01)2 results in (011011.010)2. Grouping the bits in groups of 3 about the radix point, interpret the number as follows: 011 = 3; 011 = 3; Dot 010 = 2: 33.2 (2^k conversion method). Here is how you can visualize it in rows:
011011.010 | | | 3 3 . 2