Select the most appropriate option that can substitute the highlighted segment in the given sentence. If there is no need to substitute it, select ‘No substitution’.
I am working hard in order to earn a decent living.

Correct option is D

Explanation:

The given sentence is already grammatically and idiomatically correct. Let’s break it down:

• “Working hard” is a common expression indicating putting in great effort.

• “In order to” expresses purpose — which is appropriate here.

• “Earn a decent living” is a standard collocation that means to make enough money to live comfortably, and it fits the sentence naturally.

So, no substitution is needed.

Grammar & Usage Rule:

• “Earn a living” is an idiom meaning to make money to support oneself.
  ️ Example:She earns a living by tutoring students.

• The phrase “a decent living” implies that the earnings are modest but sufficient.
  ️ Example:He earns a decent living through freelance work.