1, 2, 3, 4, 5, 18→ 6  $30-5-1=24$, $24\div2=12$  $$6+12=18$$ 
From $1$ to $30$, how many integers can be chosen at most to ensure that no two of chosen numbers sum to $36$? 
A: $$15$$ 
B: $$16$$ 
C: $$17$$ 
D: $$18$$ 
E: $$19$$ 