A few of the questions seemed odd, or mixing implementation specifics with standardize.
Edit: s/width/range/
The point being made is that the default signedness of char can be different from platform to platform, and the default can be confusing to people who associate the char type with binary data. Better to use int8_t and uint8_t when you want a portable signed or unsigned 8-bit number. int8_t is always signed, and uint8_t is always unsigned.
> Also assume that x86 or x86-64 is the target. In other words, please answer each question in the context of a C compiler whose implementation-defined characteristics include two's complement signed integers, 8-bit chars, 16-bit shorts, and 32-bit ints. The long type is 32 bits on x86, but 64 bits on x86-64 (this is LP64, for those who care about such things).