✔ 最佳答案
The answer is A.
Widen tax base = Increase the number of people eligible for paying tax.
A. A reduction in the tax allowance means fewer people have their income below the allowance level and can be exempt from tax payment, and more poeple will fall into the tax bracket to pay tax. So tax base is widen.
B. Cancellation of first registration tax on motor vehicles means fewer people need to pay tax. So tax base should be narrowed instead.
C. D. These practices alters the amount of tax that needs to be paid by the existing taxpayers. Nothing is done to increase the number of people eligible for paying tax.