Hey there!
Your answer is option "A."
It is very important to follow instructions while assembling something so that way when you finished building it, you finish what you are building the way you would want it to be.
Reading information - that would only help if you needed information for something such as an essay about the past.
Read for entertainment - that would only entertain you, not guide you.
Compare and contrast - you are only comparing things, again, not guiding.
Final answer:
Option "A."
Hope this helps you.
Have a great day!