1. **Problem Statement:** A hot air balloon rises at a steady rate of 15 meters per minute. We need to find its height after 6 minutes. 2. **Formula Used:** Height $h$ after time $t$ when rising at a constant rate $r$ is given by: $$h = r \times t$$ 3. **Given Values:** - Rate $r = 15$ meters per minute - Time $t = 6$ minutes 4. **Calculation:** $$h = 15 \times 6 = 90$$ 5. **Interpretation:** The balloon's height after 6 minutes is 90 meters. 6. **Answer:** The correct choice is (A) 90 m.