Solve \[ -3 x \leq 0.9 \] Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. The solution set is (Type your answer in interval notation. Use integers or decimals for any numbers in the expression.) B. The solution set is $\varnothing$.

Step 1 ：The inequality is -3x ≤ 0.9.

Step 2 ：To solve for x, we need to divide both sides by -3.

Step 3 ：However, when we divide or multiply an inequality by a negative number, the direction of the inequality sign changes.

Step 4 ：So, the inequality becomes x ≥ -0.3.

Step 5 ：Final Answer: The solution set is $x \geq 0.3$. In interval notation, this is $[0.3, \infty)$. So, the correct choice is A. The solution set is $[0.3, \infty)$.