Answer: d. Kamal loses any surplus he had.
Step-by-step explanation:
The Consumer Surplus is defined as the difference between what a customer is willing to pay for a good minus the price of the good/ the price they pay.
Kamal was willing to pay $320 and the price was initially $300 which meant that he had a surplus of $20. The price has now increased to $320 which is the amount he is willing to pay so there is no longer a surplus. Kamal loses any surplus he had.