What is an addressable cell size? This question started with a quiz question from my university:
Consider a big-endian computer system with an addressable cell size of one byte. The values in memory cells 372 to 375 are shown in the table below. What 16-bit two's complement value (expressed as a decimal number) is stored at address 374?

Address    Value
372        0xC5
372        0x5E
374        0x7F
375        0x23


One thing I'm not clear about is what exactly does "addressable cell size of one byte" mean?
Addressable cell size of one byte, in this context, means that every cell in memory contains one byte. Variables which take up more than one byte are spread across several contiguous cells.