Answer: OPTION D.
Step-by-step explanation:
Rectangles have four right angles (angles of 90 degrees).
The point of intersection of the diagonals divides each one of them into two equal parts.
Knowing this, we can conclude that:
[tex]m\angle c=m\angle b=55\°[/tex]
(Observe the figure)
Therefore, since the sum of the interior angles of a triangle is 180 degrees, we can find the value of "x":
[tex]x+m\angle c+m\angle b=180\°\\x=180\°-55\°-55\°\\x=70\°[/tex]
