Which of the following is true of the roman empire and and the roman catholic church in medieval europe?
a. both acted as a unifying force in europe.
b. both shared power equally under feudalism.
c. both passed laws banning iconoclasm.
d. both had the power to send armies across europe.

The correct answer is letter D. Both had the power to send armies across Europe. This was the time where expansion of the Roman Catholic Empire was performed through crusades. Armies were sent to different parts of Europe to spread the word of God and to also conquer new lands. 

What is true for both the Roman Empire and the Roman Catholic Chruch in medieval Europe would be that both had the power to send armies across Europe - D.

Both had increased power in this age compared to previous times. This enabled them effectively send armies across Europe and dictate the climate of the European political scene.