Is it natural and clear to say the following?
Answer: Yes, you could say that.
Let's proceed to analyze small nuances of the meaning. Consider the first definition from wiktionary:
alternative (plural alternatives)
- A situation which allows a mutually exclusive choice between two or more possibilities; a choice between two or more possibilities. [from 17th c.]
- One of several mutually exclusive things which can be chosen. [from 17th c.]
- The remaining option; something available after other possibilities have been exhausted. [from 18th c.]
When you use "alternative", either in the multiple-choice question or the referenced ELL post, you may be emphasizing the mutually exclusive aspect. Do you really want to do that?
There are more neutral words like "option", "choice", or in this case "answer".
- You have four options to pick from in question 1.
- You may choose between four different answers in question 1.
- There are four choices.
In the most ordinary, typical situations you'd probably pick one of those alternatives that I have just mentioned.
Like "option" or "choice".
You wouldn't say "alternative".
If you are going into much more detail about each of the answers, their pros and cons, and the fact that you may only choose one, then you may choose to elevate the choices to alternatives.
Also, "alternative" often plays against "Plan A", your main course of action. What is the alternative? That means, what is the second choice? That doesn't make sense when presented with four equally viable choices in a multiple choice test scenario.