What is one way of trying to determine the direction of writing?

One way of trying to determine the direction of writing is to look at the left hand side of the text and determine if there's a cramping of signs. Whichever side the cramping is on, it is suggested that the direction starts from the opposite side as words are often cramped at the end of the lines

the answer is:

c. islam and christianity

explanation:

islam and christianity are widely practiced in africa. islam is practiced due to its spread from the middle east into africa, and christianity is practiced due to the colonization of africa by the british empire.