Answer

The correct choice:

5.07 %.

Green marks that are used in calculations.

First, let's count all the applications developed over four years.

50 + 110 + 70 + 150 + 130 + 170 + 170 + 100 + 210 + 50 + 50 + 110 + 180 = 1380 apps.

Next, find out the percentage of applications that Company C developed in 2017 of all applications developed over the four years through the ratio.

(70 * 100)/1380 = 5.07%

Answer: 5.07%.