5.4.12在输入量不变的情况下，若引入反馈后，则说明引入的反馈是负反馈。 A: A．输入电阻增大 B: B．输出量增大 C: C．净输入量增大 D: D．净输入量减小

An administrator has a legacy cluster running version 4.5/ES and would like to update to version 5.5.Which of the following is a valid upgrade path？（） A: 1. Upgrade from 4.5 to 5.12. Upgrade from 5.1 to 5.5 B: 1. Upgrade from 4.5 to 5.22. Upgrade from 5.2 to 5.5 C: 1. Upgrade from 4.5 to 5.32. Upgrade from 5.3 to 5.5 D: 1. Upgrade from 4.5 to 5.4.12. Upgrade from 5.4.1 to 5.5