Astro Inc., a pharmaceutical company, wants to develop a drug to fight a new virus that is affecting people in Asian countries. To assist its team of doctors in developing the drug, the company hires two scientists who had previously conducted research on the virus. The company intends to use their expertise on the subject to create the drug. In the given scenario, Astro Inc. has most likely hired

a$.$ ancillary workers

b$.$ knowledge workers

c$.$ blue$-$collar workers

d$.$ black$-$collar workers