Correct Answer - Option 2 : 27

**Concept **

General term of an AP is given by:

a_{n} = S_{n} - S_{(n - 1)}

**Calculation:**

Here S_{n} = 3n^{2} + 5n

an = Sn - S(n - 1)

After solving above equation we get

a_{n} = 6n + 2

For 1st term, put n = 1

So, a_{1} = 1 = 6 × 1 + 2 = 8

For 2nd term, put n = 2

So, a_{2} = 14

Now, common difference = d = a_{2} - a_{1} = 14 - 8 = 6

Given a_{m} = 164

⇒ a + (m - 1)d = 164

⇒ 8 + (m - 1 ) 6 = 164

∴ m = 27