Grey Code Conversion:

To convert a number from its binary representation to its Grey code representation, we can follow the following steps:

1. Start with the most significant bit (MSB) of the binary number and copy it as it is to the Grey code number. This step is the same for both binary to Grey code conversion and Grey code to binary conversion.
2. For each bit starting from the second most significant bit (MSB-1), perform an XOR operation between the corresponding bit in the binary number and the previous bit in the Grey code number. Copy the result to the Grey code number.

Conversion Steps:

Let's convert the hexadecimal number (A5)16 to its binary representation first:

(A5)16 = (10100101)2

Now, let's convert the binary number (10100101)2 to its Grey code representation:

1. The most significant bit (MSB) is 1, so we copy it as it is to the Grey code number: (1)
2. For the second bit, perform an XOR operation between the second bit (0) in the binary number and the previous bit in the Grey code number (1). The result is 1. Copy this result to the Grey code number: (11)
3. For the third bit, perform an XOR operation between the third bit (1) in the binary number and the previous bit in the Grey code number (1). The result is 0. Copy this result to the Grey code number: (110)
4. Continue this process for the remaining bits: (1101)
5. The final Grey code representation is (1101)2, which is equivalent to (D)16.

Answer Explanation:

The Grey code for (A5)16 is (1101)2. Comparing this with the given options:

a) 11110111
b) 11010101
c) 11011111
d) 11011011

Option A (11110111) is the correct Grey code representation for (A5)16 as it matches the derived Grey code (1101)2.

Therefore, the correct answer is option 'A' (11110111).