In a speech seeking to persuade his audience to donate blood, ian explained how little time the donation process would take from their busy schedules. which of the three basic issues of persuasive speeches on questions of policy did ian address in this part of his speech

I believe the answer is: practicality

The issues of practicality in this context refers to how well the action that being promoted by the speaker would solve the issue.
To address this issue, it is very common for speaker in a persuasive speech to fully explain the specific disadvantage and advantages of each available options.

False it it a lot 

It is meant that like tapestry scientific theories often need to pull out since they are not relevant and often times the whole chain of theories may be pulled out.