Step 1: Understanding the Question.
We simply need the rupee value of the PF deduction each month.
Step 2: Key Formula or Approach.
The PF deduction is stated as a percentage of the basic salary, so multiply the basic salary by that percentage.
Step 3: Detailed Explanation.
The basic salary is Rs. 5,000 and the PF deduction is 10 percent of it:
\[
0.10 \times 5000 = 500
\]
The PF percentage is applied to the basic salary alone, not to the gross income of Rs. 6,000 or the net income of Rs. 5,500. Applying it to either of those larger numbers by mistake would wrongly give Rs. 600 or Rs. 550, so it is worth being careful about which base the question intends.
Step 4: Final Answer.
The monthly PF deduction is Rs. 500, so option (a) is correct.
\[ \boxed{Rs.\ 500} \]