In order to “know your audience,” you should be aware of a.
Their ages
c.
What they plan to do after graduation
b.
What they do for fun
d.
What they are interested in

  i think you forgot to put the options but if your reffering to this question then your answer will be "b"  a. add "to" to the base form to create an adjective.b. when the subject of a sentence is singular, add "–s" to the base form.c. add "–ed" to irregular base forms to form the past participle.d. do not use a base form with plural subjects

You just answered the question