Answer: 44%
Explanation:
Since we have 100 people, each person is one percent.
49 people preferred A, so we can subtract 49 from 100.
100 - 49 = 51
7 people didn't have an opinion, so we can subtract 7 from 51.
51 - 7 = 44
That means that 44 people preferred B, which is 44%