Meaning of 'keep up with the latest developments'

[Ben]

Test No. incompl/advan-24 "Employment and Training", question 8

The pace of change in that industry is so fast that staff find it hard to ......... the latest developments.

(a) hold on to
(b) keep on to
(c) hold up with
(d) keep up with

Test No. incompl/advan-24 "Employment and Training", answer 8

The pace of change in that industry is so fast that staff find it hard to keep up with the latest developments.

Correct answer: (d) keep up with
_________________________

COULD YOU GIVE ME THE ANSWER AND EXPLAIN ME WHY PLEASE

Ben

[Torsten]

The answer is keep up with the latest developments (as you can see on the screen) and it means to stay up to date.

TOEIC listening, photographs: Walking on the street