How do u subtract a mixed number with a fraction

So you put the mixed number into an improper fraction 
Ex:
1 6/12 
12 times 1 plus six is 18
18/12 minus 1/3 is 14/12

Mulitply the whole number to the denominator(the number on the bottom) and add it to the numerator(top one). Then subtract normally by finding the lowest common multiple of the denominators, converting the fractions to the new denominators, and subtracting the new numerators. Simplify if necessary. 

Ithink the answer should be b.