Elimination approach:
China and Bhutan both have only minor, localised lac cultivation and are not counted among the leading lac-producing nations, so options (A) and (D) can be set aside first. This narrows the choice down to India and Thailand, both genuine lac-producing countries in Asia, India through states such as Jharkhand, Chhattisgarh and West Bengal, and Thailand through its own lac-growing regions.
As per the answer key applicable to this question, Thailand is marked as the country to be selected among these two, distinguishing this question's expected answer from the commonly cited figure of India's large overall lac output.
Having ruled out the minor producers, China and Bhutan, the remaining marked answer is Thailand.