The answer is (b.) All states. All 50 states in US now have 21-year-old minimum drinking age laws.According to the National Drinking Age Act of 1984, anyone who will allow a person who is 21 years old and below to purchase any alcoholic beverages will be punished by deducting 10% in his/her federal highway apportionment.
Look for (context) clues when you do not know the meaning of words in a sentence or paragraph!!
Answer- CONTEXT
An intervening period of time
