I enjoy the text, these are my answers
Question 1.
That depends on the business but in general is better the option
b) Multiple
Diversification in multiple areas is better that bet all in on just one.
Question 2.
If my expenses don't double it as well I will be able to buy
c) More
Question 3.
If is a just one time interest of plus 3% is better the option
b) $100 plus 3%
Question 4.
If you don't cash out money the bank will give you
a) More in second year
Question 5.
The compund interest did the job so will have
c) More than $150
🙌
You got all correct except for 2. The answer is b, the same, because both expenses and salary doubled. However from your comment, it seems you got this in principle, I guess you might have overthought the question and didn't consider "prices of things you buy" to be equivalent to "expenses".
Tell your friends to stay away