Which Of The Following Should Be The Base Case For The #326

If(sum%2!=0) return false; if(sum==0) return true;

If(sum%2!=0) return false; if(sum==0) return true; if (n ==0 && sum!= 0) return false; 

if (n ==0 && sum!= 0) return false; 

if(sum<0) return true; if (n ==0 && sum!= 0) return false;