Answer: a. 234
Explanation:
Following the conditions,
the first digit "2" being the answer when third digit "4" is divided by 2, that leaves us with
4/2= 2
The second condition beinf that the second digit "3" and third digit "4" add up to 7.
3 + 4 = 7
And the last condition being that second digit "3" mnus first digit "2" gives us 1 when solved.
3 -2 = 1
This ends up giving us the digits 234 as the code for R.