When did this event happen?

Draw conclusions  why might a cause like italian unification successfully draw people of very different backgrounds together?  

An educatethe yuan dynasty was responsible for which of the following: i. improving the road system ii. increasing sea trade with india and south east asia. iii. extending the canal system iv. brutal warfare and ruthless killing of people in order to take over china. a. i & iii c. iv only b. ii only d. all of the above member of the government

What is the acronym to remember when evaluating source information?