Eighty-five crores, three lakh fifty-five thousand thirty-nine is the same as ___________.
A. 85,03,55,039
B. 85,03,55,39
C. 8,53,55,39
D. 8,53,00,539

Hint: To write the number given in the Indian system of numeration in the numeral form, we have to focus on the basic number system and the number of digits used. We will also focus on each digit of the given number, to represent it in numerical form.

Complete step-by-step solution:
It is given in the question that we have to represent eighty-five crores, three lakh fifty-five thousand thirty-nine in the numerical form, so we will focus on each digit of the given number. That is, first we will split eighty-five crores, three lakh fifty-five thousand thirty-nine into four parts.
So, we can write it as:
Eighty-five crores + three lakh + fifty-five thousand + thirty-nine.
If we write Eighty-five crores in the numerical form, we will get,
$ \Rightarrow 850000000$
If we write three lakhs in the numerical form, we will get,
$ \Rightarrow 300000$
If we write fifty-five thousand in the numerical form, we will get,
$ \Rightarrow 55000$
If we write thirty-nine in the numerical form, we will get,
$ \Rightarrow 39$
So, on adding all the above values, we get,
$\therefore 850000000 + 300000 + 55000 + 39 = 850355039$
Thus, eighty-five crores, three lakh fifty-five thousand thirty-nine is the same as $850355039$.

Hence, option (A) is the correct answer.

Note: In these types of questions, even though the question is very simple, students often tend to make mistakes as the numbers given are quite lengthy. So, in order to reduce the chances of errors, we can focus on each digit by splitting the given number into parts. This is the best and the correct method to convert any number given in words into its numerical form.