Representation of unsigned integer on a little endian, big endian computer
If the numerical value of a 2-byte unsigned integer on a little endian computer is 255 more than that on a big endian computer

According to the dictionary, the definition of &quot;numerical value&quot; is &quot;a real number regardless of its sign&quot;, in other words absolute value. Since the integer is unsigned, its numerical value is itself, and that will not change no matter how the integer is stored, little or big endian style, written on a napkin with lipstick in base seven, notches on a bedpost, or whatever. Therefore, the first line of the question is meaningless, which is always a nice start.
Additionally, the question confuses memory representation and integers. Two bytes in memory that look like (0x00,0x01) represent the integer 0x0100 in little-endian mode, but you can't say &quot;let's add 255 to (0x00,0x01)&quot; because (0x00,0x01) is not the number 0x0001 although it looks like it.
A correctly worded question would be:
&quot;There are two bytes in memory. A big-endian cpu reads them with a uint16 load instruction and gets an uint16 value. A little-endian cpu reads the same two bytes and gets an uint16 value that is 255 higher than the big-endian cpu's value. What are the two bytes in memory?&quot;
(One could also ask what uint16 one of the cpus gets)
Then it's pretty simple:
Memory    uint16     uint16
dump      read by LE read by BE
0x66 65   0x6566     0x6665
0x65 66   0x6665     0x6566    correct
0×00 01   0x0100     0x0001    correct
0×01 00   0x0001     0x0100
0×42 43   0x4342     0x4243    correct
0×43 42   0x4243     0x4342


According to me, answer should be A,D. But according to some of my colleagues, answer is B,C.

Having nuked the question, let's play jeopardy and try to figure out what question you and your colleagues are answering.
Basically, to misquote a famous crook, you're having a disagreement over what the word &quot;represents&quot; represents. One thinks it is the memory representation in little-endian (although it is written wrong in the question, and honestly if the word &quot;memory&quot; was mentioned it wouldn't hurt for ease of comprehension) and the other thinks it's the integer itself (probably because the 0x values are written as integers not bytes). So you're both picking from a different column of my table above.
We will have to wait for the end of the war between little endians and big endians to know what the peace treaty says about who's right.
Another way to not fix the question would be: If the memory representation of a 2-byte unsigned integer on a little endian computer looks like it is 255 more than that on a big endian computer to a human reading the memory bytes in big endian order, which of the following choices represent(s) the unsigned integer?
However, this reveals to all the rampant systemic endianness supremacy asserting that humans of the wrong endianness are lower-class citizens. This implicit endianness bias and oppression must stop! As of today, the DIE commitee dictates that everyone will switch to the more inclusive and safe middle-endianness, and both-endians colonizers will be sentenced to pay reparations to native middle-endians.