The given data shows the number of mobiles (in thousands) manufactured by companies C-1, C-2, C-3 and C-4 in 2017, 2018 and 2019.

Which company witnessed the highest increase in manufacturing from 2017 to 2018?

C-1

Increase in manufacturing from 2017 to 2018 in C1 = 65 - 59 = 6

Increase in manufacturing from 2017 to 2018 in C2 = 67 - 62 = 5 

Increase in manufacturing from 2017 to 2018 in C3 = 71 - 68 = 3 

Increase in manufacturing from 2017 to 2018 in C4 = 62 - 59 = 3 

So , Highest Increase in manufacturing from 2017 to 2018 is for  C1 .