Answer & Solution
Answer: Option A
Solution:
$$\eqalign{
& \log \frac{a}{b} + \log \frac{b}{a} = \log \left( {a + b} \right) \cr
& \Rightarrow \log \left( {a + b} \right) = \log \left( {\frac{a}{b} \times \frac{b}{a}} \right) \cr
& \Rightarrow \log \left( {a + b} \right) = \log 1 \cr
& So,\,\,\,a + b = 1 \cr} $$