I am in karachi, because Karachi is a city and you can't be "at" a city. Saying I'm at only works if it a place such as a grocery store or a mall, but does not apply to cities or countries.
True because it tells about big picture
<span> Make certain that something shall occur or be the case</span>
Answer: It means you have to plan it out, as in understand what and how you're going to write the letter.
Hope this helps!
I think it is B because It sounds like the answer
