Question

which of these technological advances has improved flu vaccines?
a. virus culturing
b. antiviral drugs
c. mri scans
d. the internet

Explanation:

Flu vaccines are developed by growing flu viruses to produce antigens. Virus culturing is the process of propagating viruses in a controlled environment, which is essential for vaccine production. Antiviral drugs treat infections, not improve vaccines. MRI scans are diagnostic tools, and the Internet is unrelated to vaccine manufacturing.

Answer:

A. Virus culturing