Question 863689
take 4n+5 and sub in the position of a term and see if the right number is the result
lets look at position 2 
4n+5=
4*2+5=
8+5=
13
look at C)
the second number is 13
C) Let's try one more to be sure
try position 4 and result 21
4*4+5=21
16+5=21
21=21
it works