Choose the idiom/phrase that can substitute the highlighted group of words meaningfully.
You must keep it in mind because it's important to remember that living in cities is very expensive.

Correct option is D

The correct phrase is Bear something in mind, which means to remember or consider something important.
Explanation: The highlighted phrase "keep it in mind" has the same meaning as "bear something in mind," which is the more idiomatic choice. Example: Bear in mind that deadlines are strictly enforced.
Meanings of the other options:
· Beat the brains: (बहुत सोचना) Refers to making a great mental effort. Example: I had to beat my brains to solve the problem.
· In the dark: (अनजान होना) Refers to being unaware or uninformed. Example: I was kept in the dark about the plans.
· In seventh heaven: (बेहद खुश होना) Means to be extremely happy. Example: She was in seventh heaven after winning the lottery.