Let's try something, we know that the mole #-=6.022xx10^23# items of stuff. For the purposes of this question, let's say the mole was a round dozen, i.e. 12 individual items.
And we rewrite the question to give:
#"How many ATOMS are there in the following quantities?"#
#"a. ONE dinitrogen molecule"#;
#"b. 1 DOZEN dinitrogen molecules"#;
#"c. ONE"# #NO_2# #"molecule"#;
#"d. ONE DOZEN nitric oxide molecules"#.
So instead of the mole, I have used another VERY POPULAR collective number, the dozen. And the dozen is commonly used because I can keep a tally with my thumb and the finger joints of the ONE HAND.
And so for #"a, b, c, d,"# I can write the answers as #2,24,3,36.# Clearly #d.# CONTAINS the most number of atoms. Are you following me? And in the question you were asked, you replaced the #"dozen"# with another (MUCH LARGER) collective number, #"the mole"#, which is specified to be equal to #6.022xx10^23#. It is important that you incorporate this idea of moles into your understanding. It will save you a lot of grief.
See this answer and here for another spray.