Which of the following is the best example of the acquisilion of human capital?

A$.$ A government$-$sponsored program increases the amount of investment available per worker.

B$.$ A computer chip manufacturer introduces a faster processor for micro$-$computing,

C$.$ A worker takes a training course that increases his$/$her productivity.

D$.$ A worker receives new machinery enabling him$/$her to do the amount of work that was formerly done by two workers.

E$.$ A worker communicates more quickly and accurately with suppliers because of upgrades to communications software.