Step 1: Understanding nutrient preservation methods.
- Freezing (A): Preserves most of the nutrients in fruits and vegetables with minimal loss.
- Using preservatives (B): Helps prevent spoilage and nutrient degradation.
- Drying and blanching (C): Drying removes moisture to slow microbial growth, while blanching preserves color and nutrients.
Step 2: Selecting the correct option. Since all listed methods help to reduce nutrient loss, the correct answer is (D) All of the above.
A closed-loop system has the characteristic equation given by: $ s^3 + k s^2 + (k+2) s + 3 = 0 $.
For the system to be stable, the value of $ k $ is: