Correct option is A
Increase of commission in 2016 = 27800 – 26200 = 1600
Increase of commission in 2017 = 28200 – 27800 = 400
Increase of commission in 2018 = 29100 – 28200 = 900
Increase of commission in 2019 = 29400 – 29100 = 300
Increase of commission in 2020 = 30000 – 29400 = 600
Commission earned by the salesman C showed the highest increase that of the preceding year in 2016
