Consider the traditional UNIX system structure. (20 points)

a. How is the kernel defined? (5 points)

b. As the traditional UNIX kernel grew over time, it was replaced by the layered approach. What benefits did this layered approach provide? (5 points)

c. As the kernel continued to grow, the microkernel system structure was invented. What was the basic idea of the microkernel? (5 points)

d. Are assemblers, compilers, and other software development environments part of the kernel? If not, what are they? (5 points)