Step 1: Understanding the intercept form of the equation of a line.
The intercept form of the equation of a line is given by:
\[
\frac{x}{a} + \frac{y}{b} = 1
\]
where \( a \) and \( b \) are the x- and y-intercepts, respectively.
Step 2: Explanation of options.
(A) \( \frac{x}{a} + \frac{y}{b} = 1 \): Correct. This is the correct form of the intercept form of the equation of a line.
(B) \( \frac{x}{a} + \frac{y}{b} = ab \): Incorrect. This is not the correct form of the intercept equation.
(C) \( ax + by = c \): Incorrect. This is the general form of a linear equation, not the intercept form.
(D) None of these: Incorrect. Option (A) is correct.
Step 3: Conclusion.
The correct answer is (A) \( \frac{x}{a} + \frac{y}{b} = 1 \).
Final Answer:} \( \frac{x}{a} + \frac{y}{b} = 1 \).