The second term in an arithmetic sequence is 10 and the fifth term is 22. if the first term is a1, what is an equation for the nth term of this sequence?

In an arithmetic sequence, the nth term is the first term + (n-1)* difference
the fifth term=the second term +(5-2)*difference
22=10+3d
d=4
the first term=the second term-the difference=10-4=6
the nth term =6+4(n-1) or  or 10+4(n-2), 

Ithink not so sure but i tried it out and came out to be b