Answer:
The X register in HCS12 is 16 bits wide.
Explanation:
HCS12 CPU has the following registers:
Two 8 bit accumulators, A and B.
16 bit index registers X and Y.
16 bit stack pointer.
16 bit program counter
A conditional code register.
So, the correct answer is
The X register in HCS12 is 16 bits wide.
