a. double num1, int num2 =0;
b. double num1, int num2 =0;
c. int num1, num2 = 0;
d. int num1 = 0, num2 = 0;
Answer:
a. double num1, int num2 = 0;
Explanation
After declaring a variable or a group of variables of same datatype, semi-colon should be placed. In the above option a after declaring num1 as double, a semi-colon should have been placed, then that declaration would have compiled correctly.