Natural remedies are usually more effective and safer because they are thoroughly tested.
a. true
b. false

That statement is False

Natural Remedies does not need to be tested by the FDA , so they are not thoroughly tested.

And as for effectiveness, most natural remedies only effective in treating mild illness such as sore throat, itch, slight fever, etc, they are not more effective than generic drugs

The attention line is placed above the recipient line, that is, above the name of the firm to which the mail-piece  is directed.