Which of the following is a parallelogram?  Choose the correct choice from the following choices.
A) 120,50,120,50(angle in deg)
B) 120,30,130,20(angle in deg)
C) 90,90,90,90(angle in deg)
D) a & c
E) none
sum of adjacent angles is 180 degrees.   ANSWER:90,90,90,90(angle in deg)
<result>C</result>
Which of the following is a parallelogram?