Which of the following is an infinite set?
The set of all lines parallel to Y-axis
An infinite set is a set that is not a finite set. A finite set is a set that has a finite number of elements.
A - There are infinite lines parallel to y-axis
B - Though we may not count number of atoms, we can be sure that the number is large and it is a finite number.
C - Number of elements in the set of letters in English alphabet is finite.
D - Number of circles that can have centre as (0, 0) and radius of 1cm is finite.
So, A is an infinite set.