B-60
Step-by-step explanation:
If he sold 8 vanilla, 28 double scoop and 12 chocolate chip, it means he sold 12 chocolate chip out of 48. So he sold 12/48 chocolate chip, which equals 1/4. If we write it in percentages, we will see that 1/4•100%=25%. Now we need to know how many chocolate chips would be sold in next 240 cones. In conclusion, we need to calculate 25% of 240. So if 240 is 100% and X is 25%, then 240•25=100X. If we solve that equation, we will see that X=60, so 25% of 240 equals 60. In conclusion, the right answer is B.