The largest value (in hex) that can be loaded into register a of hcs12 is (points : 2) 0x8.
0x255.
0x65535.
0xff.

0xFF.

Explanation:

The Register A of HSC12 is an 8-bit register.So the maximum value for 8 bit is 8 1's (11111111). So the decimal value for the maximum 8 bits is 255 but all the options given are in hexadecimal so among the given options only 0xFF has the value of 255 in decimal  F=(1111)₂.So two F's make 8 bits and their decimal value is 255.

i think the answer would be a