The correct answer to this open question is the following.
Although there are no options attached we can say the following.
Citizens in many countries can vote at age 18. Which country requires citizens to wait until they are 20 to vote?
There are some countries that require citizens to wait until they are 20 to vote. These are Cameroon, Bahrain, Kuwait, Lebanon(21 years old), Malaysia, Oman, among others.
The average age to vote is 18 years old, although there countries that are lowering the age to vote to 16 years old, as is the case of Argentina, Cuba, and Scotland.
Governments consider that when an individual is 18 years old, he/she is mature enough to freely decide without the influence of his family, friends, and can cast his vote from his own conviction, according to his beliefs and interests.