Answer:
A. Total expenditure on light bulb increases after the tax.
Explanation:
The government has imposed tax on the light bulb production and the new price after the tax is $14. The price before the tax was $12 and the marginal cost before tax was $9. There was a profit of $3 for the producers of the light bulb. The tax burden is shifted to the consumers of the bulb since the marginal price after tax is $12. Total expense for the production of bulb has increased due to tax.