Which of the following statements about CPUs are FALSE?

Select all answers that apply

a$)$

A CPU attaches directly to a motherboard.

b$)$

The clock speed of a processor is the number of instructions it can process per second.

c$)$

Multi$-$core processors can process more instructions at a given time than single$-$core processors.

d$)$

When comparing two processors, the processors that has the faster clock speed is the better processor.