Capitalization means using a capital letter at the head of a word.
We always capitalize geographical names.
United States of America
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
The correct answer is
The smallest number is the one that comes first while counting.
To arrange the given numbers in order from smallest to greatest, find the smallest number among all the given numbers.
21 is the smallest number.