How does specialization by workers benefit the firms employing them?

How does specialization by workers benefit the firms employing them?

a. Workers are happier and demand less pay when they are allowed to specialize at specific tasks.
b. Governments give subsidies to firms in order to encourage specialization by workers.
c. Workers who specialize become more efficient and thereby increase productivity.
d. Workers who specialize suffer much less illness than other workers and thereby save the firm the cost of days lost due to sickness.