What is the difference between valid and reliable assessments?

Even though valid and reliable are both very similar, they are also somewhat different. They do however rely upon each other. Valid is that stating that something is legally or officially accepted, where Reliable is simply stating that you can trust what you are using. Validity needs to rely on things, which is why they both are so hard to tell apart. For example, just because a Lab result is valid, it does however still need to rely on other things more often then not in order to make it reliable. 

I believe that D is the answer to question 2 on your paper.

Opinions are the expression of someone's beliefs or bias, and usually opinionated statements like these will be less focused on the facts or lacking of valid evidence for their claims

For me, it just helps to think about how the statement presents itself, like if it uses persuasive appeals to emotions or ethics or not

Regarding the last answer choice, you can ask yourself, "what makes reading a rewarding solitary activity?" and "how has social media greatly improved reading experiences?" or "who would agree with this statement?"

The other three options don't sound biased, and back up their claims with evidence, so I would say that D is the best choice. hope this helps!!