Testbook Imp. TOC question

Question

Consider a CFG G that describes the language $L(G)$. Suppose G may have $\epsilon$ productins. If a non-empty string $w$, of length $n$ can be derived in m steps. What is the maximum number of nodes in the parse tree for w?

a). m + n

b). m + n - 1

c). 2m + n

d). 2m + n - 1

Comments

i can have so many non-terminals which derives null productions..like
if i want to write a grammar that accepts language {ab}
i can write
A-->BCDF
B-->a
D-->b
D-->eps
F-->eps
like this beside F, i can put many non-terminals and make them derive only epsilon.
i think some data is missing in question..or i understood it wrong :/