We are given the inequality:
\[
|3x - 4| \leq 5.
\]
By the definition of absolute value, we know that:
\[
|A| \leq B \text{ implies } -B \leq A \leq B.
\]
Thus, we can rewrite the inequality as:
\[
-5 \leq 3x - 4 \leq 5.
\]
Step 1: Solve the inequality
Add 4 to all parts of the inequality to isolate the term with \( x \):
\[
-5 + 4 \leq 3x \leq 5 + 4
\]
\[
-1 \leq 3x \leq 9.
\]
Step 2: Divide by 3 to solve for \( x \)
\[
\frac{-1}{3} \leq x \leq \frac{9}{3}
\]
\[
-\frac{1}{3} \leq x \leq 3.
\]
Thus, the solution to the inequality is:
\[
x \in \left[ -\frac{1}{3}, 3 \right].
\]
Therefore, the correct answer is option (A), \( \left[ -\frac{1}{3}, 3 \right] \).