Select the correct answer form each drop-down menu. First box options:
a. subtraction property of equality
b. linear pair theorem
c. vertical angles theorem
d. angle addition postulate

Second box options:
a. angle addition postulate
b. vertical angles theorem
c. linear pair theorem
d. subtraction property of equality

Third box options:
a. angle addition postulate
b. vertical angles theorem
c. linear pair theorem
d. subtraction property of equality

Fourth box options:
a. linear pair theorem
b. vertical angles theorem
c. subtraction property of equality
d. angle addition postulate

(Just type the answer/letters.)