Correct Answer: D
Analysis:
A. 消失(xiāoshī) is the word for “Vanish.”
The character 消(xiāo) means to eliminate and 失(shī) means to lose or miss.
B. 激化(jīhuà) is the word for “Become acute.”
The character 激(jīhuà)means to arouse and 化(huà)means to turn or change into.
C. 增加(zēngjiā) is the word for “Increase.”
The characters 增(zēng) and 加(jiā) both mean to increase or add.
D. 缓和(huǎnhé) is the word for “Ease up.”
The character 缓(huǎn) means slow or gradual and 和(hé)means and or together.