Answer:
A
Step-by-step explanation:
X corresponds to the angle directly above it. ( the one adjacent to or beside 75) That means that x and the angle above it are the same measure. 75 and the angle beside it are a linear pair (adjacent angles on a line that sum to 180 degrees) linear pairs are always supplementary. So angle x has to be 105. 105 + 75 = 180.
Supplementary just means the sum of the two angles is equal to 180. Complimentary is wrong because it means the sum of the two would equal 90 degrees.