$17 + 2 \times 2 = 21$ 
Lily\textquotesingle s age plus Judy\textquotesingle s age was equal to $$17$$ two years ago. What is the sum of their ages this year? (adapted from 2016 Math Kangaroo Problem, Level 1-2, Question \#16) 
Options:
A. $$16$$ 
B. $$17$$ 
C. $$18$$ 
D. $$19$$ 
E. $$21$$ 