Number of nodes

Question

I am getting option (D). But answer is given as (B). Please check.

Answer 1

Answer :Option (B)

Let's Understand this with an example.

Let CFG be,

S -> aSa | bSb | ϵ

Now I took w=aa, 

so, |w|=2, and when you will derive it on pen and paper you will find that m=2

And there will be 5 nodes. a,s,s,a,ϵ.

Option B satisfies this relation as 2*2+2-1=5.