Concept:The question tests the ability to identify the incorrectly spelt word among the given options.
Explanation:The incorrectly spelt word is "Subsistance".
Its correct spelling is "Subsistence".
Subsistence - (जीवन निर्वाह) the state of having just enough resources to stay alive.
Example: They lived a subsistence lifestyle, growing their own food and relying on hunting and fishing.
Let us verify the other words:
Benchmark - (मानक) a standard or point of reference against which things may be compared.
Knight - (सामंत) a medieval nobleman trained to fight on horseback.
Aggravate - (ख़राब करना) to make a bad situation worse.
All these three words are correctly spelt.
Only "Subsistance" contains a spelling error.
Answer:Option
D - Subsistance.
Thus, the correct answer is Option
D.